Document And Entity Information - USD ($) $ in Thousands	12 Months Ended
Document And Entity Information - USD ($) $ in Thousands	Dec. 31, 2015	Feb. 19, 2016	Jun. 30, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	RPX Corporation
Document Type	10-K
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2015
Entity Common Stock, Shares Outstanding		51,603,872
Amendment Flag	false
Entity Central Index Key	0001509432
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	No
Document Fiscal Period Focus	FY
Entity Public Float			$ 894,424

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Preferred Stock, Value, Issued	$ 0	$ 0
Current assets:
Cash and cash equivalents	94,983	78,019
Short-term investments	231,015	239,514
Restricted cash	701	584
Accounts receivable	13,905	24,793
Prepaid expenses and other current assets	12,643	3,466
Deferred tax assets	0	4,400
Deferred Tax Assets, Net	16,619	4,493
Total current assets	353,247	350,776
Patent assets, net	254,560	236,349
Property and equipment, net	4,733	4,151
Intangible assets, net	1,801	3,526
Goodwill	19,978	19,978
Restricted cash, less current portion	727	1,091
Other assets	6,896	26,100
Deferred Tax Assets, Net, Noncurrent	16,619	93
Total assets	658,561	642,064
Current liabilities:
Accounts payable	959	235
Accrued liabilities	14,842	14,257
Deferred revenue	110,921	133,316
Deferred payment obligations	2,383	0
Other current liabilities	467	640
Total current liabilities	129,572	148,448
Deferred revenue, less current portion	4,731	2,893
Other liabilities	7,779	5,678
Total liabilities	142,082	157,019
Common stock	5	5
Additional paid-in capital	344,610	326,280
Retained earnings	172,115	158,868
Accumulated other comprehensive income (loss)	(251)	(108)
Total stockholders' equity	516,479	485,045
Total liabilities and stockholders' equity	$ 658,561	$ 642,064

Consolidated Balance Sheets (Parenthetical) - $ / shares shares in Thousands	Dec. 31, 2015	Dec. 31, 2014
Common stock, par value per share (in dollars per share)	$ 0.0001	$ 0.0001
Common stock authorized (in shares)	200,000	200,000
Common stock issued (in shares)	53,489	54,062
Common stock outstanding (in shares)	53,489	54,062
Preferred stock par value per share (in dollars per share)	$ 0.0001	$ 0.0001
Preferred shares authorized (in shares)	10,000	10,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue	$ 72,831	$ 68,212	$ 67,551	$ 83,287	$ 291,881	$ 259,335	$ 237,504
Cost of revenue	39,475	37,639	36,985	34,759	148,858	124,435	110,771
Selling, general and administrative expenses	20,199	18,773	18,997	19,459	77,428	71,679	62,525
(Gain) loss on sale of patent assets, net	0	0	(592)	0	(592)	(707)	126
Operating income	13,157	11,800	12,161	29,069	66,187	63,928	64,082
Other income (expense), net	(2,619)	876	934	121	(688)	354	213
Income before provision for income taxes	10,538	12,676	13,095	29,190	65,499	64,282	64,295
Provision for income taxes	5,011	4,842	5,065	11,159	26,077	24,941	23,512
Net income	$ 5,527	$ 7,834	$ 8,030	$ 18,031	39,422	39,341	40,783
Net income available to common stockholders:
Basic					39,422	39,341	40,763
Diluted					$ 39,422	$ 39,341	$ 40,763
Net income available to common stockholders per common share:
Basic	$ 0.10	$ 0.14	$ 0.15	$ 0.33	$ 0.72	$ 0.74	$ 0.78
Diluted	$ 0.10	$ 0.14	$ 0.14	$ 0.33	$ 0.71	$ 0.72	$ 0.76
Weighted-average shares used in computing net income available to common stockholders per common share:
Basic					54,432	53,444	51,956
Diluted					55,410	54,818	53,652

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net income	$ 39,422	$ 39,341	$ 40,783
Unrealized gains (losses) on available-for-sale securities:
Unrealized holding gains (losses) arising during the period	(572)	(156)	67
Less: reclassification adjustment for (gains) losses included in net income	429	0	1
Net unrealized gains (losses) on available-for-sale securities, net of tax	(143)	(156)	68
Comprehensive income	$ 39,279	$ 39,185	$ 40,851

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Consolidated Statements Of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)
Balance, shares at Dec. 31, 2012		51,084
Balance at Dec. 31, 2012	$ 360,259	$ 5	$ 281,530	$ 78,744	$ (20)
Net income	40,783			40,783
Unrealized gain (loss) on available-for-sale securities, net of tax	68				68
Issuance of common stock upon exercise of stock options, vesting of restricted stock units and other common stock issuances, shares		1,618
Issuance of common stock upon exercise of stock options, vesting of restricted stock units and other common stock issuances	5,223	$ 0	5,223
Issuance of Common Stock Related to Business Acquisition	0
Vesting of stock options early exercised	66	$ 0	66
Stock-based compensation	16,192		16,192
Tax benefit of equity award deductions	3,088		3,088
Repurchase of common stock, shares		(10)
Payments for Repurchase of Common Stock	0
Stock Repurchased During Period, Value	0
Tax withholdings related to net share settlements of restricted stock units	(756)		(756)
Balance, shares at Dec. 31, 2013		52,692
Balance at Dec. 31, 2013	424,923	$ 5	305,343	119,527	48
Net income	39,341			39,341
Unrealized gain (loss) on available-for-sale securities, net of tax	(156)				(156)
Issuance of common stock upon exercise of stock options, vesting of restricted stock units and other common stock issuances, shares		1,188
Issuance of common stock upon exercise of stock options, vesting of restricted stock units and other common stock issuances	3,163		3,163
Issuance of Common Stock Related to Business Acquisition, Shares		182
Issuance of Common Stock Related to Business Acquisition	3,156		3,156
Stock-based compensation	17,747		17,747
Tax benefit of equity award deductions	1,799		1,799
Payments for Repurchase of Common Stock	0
Tax withholdings related to net share settlements of restricted stock units	4,928		4,928
Balance, shares at Dec. 31, 2014		54,062
Balance at Dec. 31, 2014	485,045	$ 5	326,280	158,868	(108)
Net income	39,422			39,422
Unrealized gain (loss) on available-for-sale securities, net of tax	$ (143)				(143)
Issuance of common stock upon exercise of stock options, vesting of restricted stock units and other common stock issuances, shares	778	1,420
Issuance of common stock upon exercise of stock options, vesting of restricted stock units and other common stock issuances	$ 5,013		5,013
Issuance of Common Stock Related to Business Acquisition	0
Stock-based compensation	17,728		17,728
Tax benefit of equity award deductions	686		686
Repurchase of common stock, shares		(1,993)
Payments for Repurchase of Common Stock				26,175
Stock Repurchased During Period, Value	(26,175)
Tax withholdings related to net share settlements of restricted stock units	5,097		5,097
Balance, shares at Dec. 31, 2015		53,489
Balance at Dec. 31, 2015	$ 516,479	$ 5	$ 344,610	$ 172,115	$ (251)

Consolidated Statements Of Stockholders' Equity (Deficit) (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2013 USD ($) $ / shares
Initial Public Offering
Stock issuance costs \| $	$ 2,915
Issuance price of common stock \| $ / shares	$ 19.00
Secondary Offering
Stock issuance costs \| $	$ 540
Issuance price of common stock \| $ / shares	$ 20.49

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities
Net income	$ 39,422	$ 39,341	$ 40,783
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	145,835	123,138	108,629
Stock-based compensation	17,594	17,656	16,115
Excess tax benefit from stock-based compensation	(1,593)	(2,598)	(3,857)
(Gain) loss on sale of patent assets, net	(592)	(707)	126
Amortization of premium on investments	6,666	6,585	6,013
Deferred taxes	(13,010)	(14,216)	(3,302)
Liabilities, Fair Value Adjustment	(3,887)	0	0
Gains (Losses) on Extinguishment of Debt	(3,000)	0	0
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	5,096	0	0
Gain (Loss) on Sale of Investments	(3,444)	0	0
Other	(60)	(500)	116
Changes in assets and liabilities:
Accounts receivable	10,888	14,006	(13,333)
Other receivables	0	0	33,775
Prepaid expenses and other assets	(17,651)	3,565	(9,376)
Accounts payable	724	(97)	(236)
Accrued and other liabilities	4,631	6,930	3,648
Deferred revenue	(21,284)	(1,634)	33,372
Net cash provided by operating activities	173,223	191,469	212,473
Cash flows from investing activities
Purchases of investments classified as available-for-sale	(273,853)	(224,548)	(210,660)
Maturities of investments classified as available-for-sale	254,360	174,650	147,052
Sales of investments classified as available-for-sale	21,650	0	1,099
Business acquisitions	(425)	(2,286)	0
(Increase) decrease in restricted cash	247	143	(1,818)
Purchases of property and equipment	(2,163)	(1,511)	(2,880)
Acquisitions of patent assets	(132,834)	(136,968)	(127,101)
Payment of Deposit for Acquisition of Intangible Asset	0	(25,000)	0
Proceeds from sale of patent assets	650	1,086	100
Payments to Acquire Assets, Investing Activities	(2,500)	0	0
Net cash used in investing activities	(134,868)	(214,434)	(194,208)
Cash flows from financing activities
Repayments of principal on deferred payment obligations	(2,935)	0	0
Proceeds from other obligations	6,270	0	0
Proceeds from exercise of stock options and other common stock issuances	4,953	3,159	5,151
Taxes paid related to net share settlements of restricted stock units	(5,097)	(4,928)	(756)
Excess tax benefit from stock-based compensation	1,593	2,598	3,857
Payments for Repurchase of Common Stock		0	0
Net cash provided by financing activities	(21,391)	829	8,252
Net increase (decrease) in cash and cash equivalents	16,964	(22,136)	26,517
Cash and cash equivalents at beginning of period	78,019	100,155
Cash and cash equivalents at end of period	94,983	78,019	100,155
Supplemental disclosures of cash flow information
Cash paid for income taxes	23,969	15,066	17,849
Non-cash investing and financing activities
Change in patent assets purchased and accrued but not paid	0	(500)	(600)
Change in fixed assets purchased and accrued but not yet paid	0	(166)	(166)
Change in other assets purchased and accrued but not paid	0	(63)	63
Patent assets and intangible assets received in barter transactions	2,203	0	0
Noncash or Part Noncash Acquisition, Net Nonmonetary Assets Acquired (Liabilities Assumed)	5,935	0	0
Issuance of Common Stock Related to Business Acquisition	0	3,156	0
Cost related to public offerings accrued but not paid	$ 0	$ 425	$ 0

Nature of Business	12 Months Ended
Nature of Business	Dec. 31, 2015
Nature of Business
Nature Of Business	Nature of Business RPX Corporation (also referred to herein as “RPX” or the “Company”) helps companies reduce patent-related risk and expense by providing a subscription-based patent risk management solution that facilitates more efficient exchanges of value between owners and users of patents compared to transactions driven by actual or threatened litigation. The core of the Company’s solution is defensive patent aggregation, in which it acquires patents or licenses to patents that are being or may be asserted against the Company’s current or prospective clients. The Company occasionally enters into agreements to acquire covenants not to sue in order to further mitigate its clients’ litigation risk. The acquired patents, licenses to patents, patent rights and agreements for covenants not to sue are collectively referred to as “patent assets.” The Company’s clients pay an annual subscription fee and in return, receive a license from the Company to substantially all of its patent assets and access to its proprietary patent market intelligence and data. In some instances, the Company accepts a payment from a client to finance part or all of an acquisition involving patent assets that may cost more than the Company is prepared to spend with its own capital resources or that are relevant only to a very small number of clients. In these instances, the Company facilitates syndicated transactions that include contributions from participating clients in addition to their annual subscription fees. In addition to the Company’s core solution, in August 2012, the Company began underwriting patent infringement liability insurance policies to insure against certain costs of litigation from non-practicing entities (“NPEs”). In March 2014, the Company formed a reinsurance company to assume a portion of the underwriting risk on insurance policies that the Company issues on behalf of a Lloyd’s of London underwriting syndicate. The Company began placing new policies under the reinsurance model in May 2014. As of and for the year ended December 31, 2015, the effect of the insurance policies that the Company has issued or assumed through its reinsurance business was not material to the Company’s results of operations, financial condition or cash flows.

Basis of Presentation and Significant Accounting Policies

12 Months Ended

Dec. 31, 2015

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Basis Of Presentation And Significant Accounting Policies

Basis of Presentation and Significant Accounting Policies

Basis of Presentation

These consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) and include the accounts of RPX and its wholly owned subsidiaries. All intercompany transactions have been eliminated.

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, contingent assets and liabilities, and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and reported amounts of revenues and expenses during the reporting period covered by the consolidated financial statements and accompanying notes. The Company bases its estimates on various factors and information which may include, but are not limited to, history and prior experience, expected future results, new related events and current economic conditions, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ materially from those estimates.

Significant estimates and assumptions made by management include the determination of:


•	the estimated economic useful lives of patent assets;


•	the determination of a best estimated selling price of a subscription to the Company’s patent risk management solution and its insurance offering;


•	the fair value of assets acquired and liabilities assumed for business combinations;


•	recognition and measurement of current and deferred income taxes, any related valuation allowances, and uncertain tax positions;


•	the fair value of stock awards issued;


•	the assumptions and methods used in deriving the fair value of deferred payment obligations; and


•	the estimated reserves for known and incurred but not reported claims.

Revenue Recognition

The Company recognizes revenue in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 605, Revenue Recognition (“ASC 605”) and related authoritative guidance. The primary source of the Company’s revenue is fees paid by its clients under subscription agreements. The Company believes the subscription component of its patent risk management solution comprises a single deliverable. The Company recognizes each subscription fee ratably over the period for which the fee applies. Revenue is recognized net of any discounts or other contractual incentives. The Company starts recognizing revenue when all of the following criteria have been met:


•	Persuasive evidence of an arrangement exists. All subscription fees are supported by an executed subscription agreement.

•

Delivery has occurred or services have been rendered. The subscription agreement calls for the Company to provide its patent risk management solution over a specific term commencing on the agreement effective date. Because services are not on an individualized basis (i.e., the Company generally performs its services on behalf of all of its clients as opposed to each client individually), delivery occurs automatically with the passage of time. Consequently, the Company recognizes subscription revenue ratably.

•

Seller’s price to the buyer is fixed or determinable. Each client’s annual subscription fee is typically based on the Company’s rate card in effect at the time of the client’s initial agreement. A client’s subscription fee is generally determined using the applicable rate card and its normalized operating income, which is defined as the greater of (i) the average of its operating income for the three most recently reported fiscal years and (ii) 5% of its revenue for the most recently reported fiscal year. The fee for the first year of the agreement is typically determined and invoiced at the time of contract execution. The fee for each subsequent year of the agreement is generally calculated and invoiced in advance prior to each anniversary date of the agreement.


•	Collectability is reasonably assured. Subscription fees are generally collected on or near the effective date of the agreement and again at or near each anniversary date thereof. The Company does not recognize revenue in instances where collectability is not reasonably assured. Generally, the Company’s subscription agreements state that all fees paid are non-refundable.

In limited instances where a subscription agreement includes a contingency clause, giving one or both parties an option to terminate the agreement and receive a full refund if contingencies are not resolved within a defined time period, revenue will not be recognized until the contingency has been satisfied. The revenue earned during the period between the effective date of the agreement and the contingency removal date is recognized on the contingency removal date. Thereafter, revenue is recognized ratably over the remaining subscription term.

The Company’s clients generally receive a term license to, and a release from all prior damages associated with, patent assets in the Company’s portfolio. The term license to each patent asset typically converts to a perpetual license at the end of a contractually specified vesting period, provided that the client is a member at such time. The Company does not view the conversion from term license to perpetual license to be a separate deliverable in its arrangements with its clients because the utility of, access to and freedom to practice the inventions covered by the patent asset is no different between a term and perpetual license.

In some instances, the Company accepts a payment from a client to finance part or all of an acquisition. The Company refers to such transactions as syndicated acquisitions. The accounting for syndicated acquisitions can be complex and often requires judgments on the part of management as to the appropriate accounting treatment. In accordance with ASC 605-45, Revenue Recognition: Principal Agent Considerations, in instances where the Company substantively acts as an agent to acquire patent rights from a seller on behalf of clients who are paying for such rights separately from their subscription agreements, the Company may treat the client payments on a net basis. When treated on a net basis, there may be little or no revenue recognized for such contributions, and the basis of the acquired patent rights may exclude the amounts paid by the contributing client based on the Company’s determination that it is not the principal in these transactions. In these situations, where the Company substantively acts as an agent, the contributing clients are typically defendants in an active or threatened patent infringement litigation filed by the owner of a patent. The Company’s involvement is to assist its clients to secure a dismissal from litigation and a license to the underlying patents.

Key indicators evaluated to determine the Company's role as either principal or agent in the transaction include, among others:


•	the seller of the patent assets is generally viewed as the primary obligor in the arrangement, given that it owns and controls the underlying patent(s) and thus has the absolute authority to grant and deliver any release from past damages and dismissal from litigation, as well the general terms of the license granted;


•	the Company has no inventory risk, as the clients generally enter into their contractual obligations with the Company prior to or contemporaneous to the Company entering into a contractual obligation with the seller;


•	the Company generally has limited pricing latitude as client contributions are based on the sales price set by the seller;


•	the Company is not involved in the determination of the product or service specification and has no ability to change the product or perform any part of the service in connection with these transactions, as the seller owns the underlying patent(s); and


•	the Company has limited or no credit risk, as each respective client has a contractually binding obligation, such clients are generally of high credit quality and in many instances, the Company collects the client contribution prior to making a payment to the seller.

In certain syndicated transactions, the Company may recognize revenue upon the sale of licenses to specific patent assets and/or upon completion of the rendering of advisory services.

Revenue recognition for arrangements with multiple deliverables. A multiple-element arrangement may include the sale of a subscription to the Company’s patent risk management solution and an insurance policy to cover certain costs associated with patent infringement litigation by NPEs, each of which are individually considered separate units of accounting. Each element within a multiple-element arrangement is accounted for as a separate unit of accounting given that the delivered products have value to the customer on a standalone basis. The Company considers a deliverable to have standalone value if the product or service is sold separately by itself or another vendor. The delivery of insurance coverage is not dependent on a client’s subscription to the Company’s patent risk management solution. While the Company believes its insurance product offering is unique, its clients are able to purchase insurance coverage as a standalone product from other providers. The Company sells the components of its patent risk management solution on a standalone basis.

The Company has determined its best estimate of selling price (“BESP”) for a subscription to our patent risk management solution based on the following:

•

List price, which represents the rates listed on its annual rate card. The Company publishes a standard rate card annually. Each client’s subscription fee is typically calculated using its applicable rate card and its normalized operating income, which is defined as the greater of (i) 5% of the client’s most recently reported fiscal year’s revenue, and (ii) the average of the three most recently reported fiscal years’ operating income of the client. Each client’s annual subscription fee is reset annually based on its normalized operating income for its most recently completed fiscal years.

The Company has determined its BESP for its insurance product based on the following:

•

Actuarially determined factors. Although the Company sells its insurance product both on a standalone basis and as a component of a multiple-element arrangement, the pricing is not affected by the subscription to our patent risk management solution. The Company uses an actuarial model that calculates an individual client’s insurance premium based on its projected annual frequency (i.e., number of claims during the policy term) and severity (i.e., the amount which it expects to settle a claim).

Accounting for Payments to Clients

The Company occasionally agrees to provide payments, discounts or other contractual incentives to clients in exchange for specified consideration. The Company accounts for such contract provisions in accordance with ASC 605-50, Revenue Recognition: Customer Payments and Incentives, which requires the Company to offset the amount of the payment, discount or other contractual incentive against revenue if the Company is unable to demonstrate both receipt of an identifiable benefit and determine the fair value of the benefit received.

Deferred Revenue

The Company generally invoices its clients upon execution of a new agreement and prior to any anniversary date for existing agreements. The Company records the amount of fees billed as deferred revenue and recognizes such amounts as revenue ratably over the period for which they apply. The Company typically records deferred revenue when it has the legal right to bill amounts owed and the applicable service period has commenced. In an instance where a term has commenced but the fees have not yet been invoiced, the Company records an unbilled receivable. Deferred revenue that will be recognized during the succeeding 12-month period from the respective balance sheet date is recorded as deferred revenue, current, and the remaining portion is recorded as non-current.

Accounts Receivable

Accounts receivable primarily includes amounts billed to clients under their subscription agreements. The majority of the Company’s clients are well-established operating companies with investment-grade credit. For the years ended December 31, 2015 and 2014, the Company has not incurred any material losses on its accounts receivable. Based upon its historical collections experience and specific client information, the Company has determined that no allowance for doubtful accounts was required at either December 31, 2015 or 2014.

Concentration of Risk

The Company is subject to concentrations of credit risk principally attributable to cash, cash equivalents, investments, accounts receivable and other receivables. The Company’s non-restricted cash balances deposited in U.S. banks are non-interest bearing and are insured up to the Federal Deposit Insurance Corporation (“FDIC”) limits. Cash equivalents primarily consist of institutional money market funds, U.S. government and agency securities, municipal bonds and commercial paper denominated primarily in U.S. dollars. Investment policies have been implemented that limit purchases of debt securities to investment-grade securities.

Credit risk with respect to accounts and other receivables is generally mitigated by short collection periods and/or subscription agreements that provide for payments in advance of the rendering of services. Three clients individually accounted for 32%, 18%, and 14% of accounts receivables at December 31, 2015. Three clients individually accounted for 28%, 24%, and 14% of accounts receivables at December 31, 2014. No client accounted for more than 10% of subscription fee revenue in any of the years ended December 31, 2015, 2014 or 2013.

Fair Value Measurements

The Company applies fair value accounting for all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis. The Company defines fair value as the price that would be received from selling an asset or that would be paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities, which are required to be recorded at fair value, the Company considers the principal or most advantageous market in which the Company would transact and the market-based risk measurements or assumptions that market participants would use in pricing the asset or liability, such as risks inherent in valuation techniques, transfer restrictions and credit risk. Fair value is estimated by applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement:

Level 1 – Valuations based on quoted prices in active markets for identical assets or liabilities and readily accessible by the Company at the reporting date.

Level 2 – Valuations based on inputs other than quoted prices included within Level 1 that are observable for assets or liabilities, either directly or indirectly through market corroboration, for substantially the full term of the financial instrument.

Level 3 – Valuations based on inputs that are unobservable.

The carrying amounts of the Company’s financial instruments, which include cash equivalents, short-term investments, accounts receivable, other receivables and accounts payable, approximate their fair values due to their short maturities. The carrying amounts of the Company's deferred payment obligations are valued using Level 3 valuation techniques which approximate fair value.

Cash and Cash Equivalents

The Company’s cash and cash equivalents principally consist of commercial paper, institutional money market funds, U.S. government and agency securities, and corporate and municipal bonds denominated primarily in U.S. dollars. Cash equivalents are highly liquid, short-term investments having an original maturity of 90 days or less that are readily convertible to known amounts of cash.

Restricted Cash

Restricted cash consists primarily of a certificate of deposit established as collateral for the Company’s office lease agreement as well as amounts held in trust. At December 31, 2015 and 2014, the Company had restricted cash (current and non-current) of $1.4 million and $1.7 million, respectively.

Short-Term Investments

The Company holds short-term investments in municipal and corporate bonds primarily maturing between 90 days and 12 months, commercial paper, U.S. government and agency securities, and equity securities. The Company considers its investments as available to support current operations. As a result, the Company classifies its investments, including those with stated maturities beyond twelve months, as current assets in the accompanying consolidated balance sheets. The Company primarily classifies these securities as “available-for-sale” and carries them at fair value in the consolidated balance sheets. Unrealized gains or losses are recorded, net of estimated taxes, in accumulated other comprehensive income (loss), a component of stockholders’ equity. Realized gains and losses are recognized upon sale or exchange. The specific identification method is used to determine the cost basis of fixed income securities sold.

The Company periodically evaluates its investments for impairment due to declines in market value considered to be “other-than-temporary.” This evaluation consists of several qualitative and quantitative factors, including the Company’s ability and intent to hold the investment until a forecasted recovery occurs, as well as any decline in the investment quality of the security and the severity and duration of the unrealized loss. In the event of a determination that a decline in market value is other-than-temporary, the Company will recognize an impairment loss, and a new cost basis in the investment will be established. During the years ended December 31, 2015 and 2014, the Company recorded an other-than-temporary impairment on its short-term investments of $5.1 million and nil, respectively, in its consolidated statements of operations within other income (expense), net.

Property and Equipment, Net

Property and equipment are stated at cost less accumulated depreciation. Depreciation is computed using a straight-line method over the estimated useful lives of the related assets, which is generally three to five years. Maintenance and repairs are charged to expense as incurred, and improvements and betterments are capitalized. When assets are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the consolidated balance sheet and any resulting gain or loss is reflected in the consolidated statement of operations in the period realized. Leasehold improvements are amortized on a straight-line basis over the term of the lease, or the useful life of the assets, whichever is shorter.

Internal-Use Software and Website Development Costs

The Company capitalizes development costs related to internal-use software and its website and records such amounts as property and equipment, net, on its consolidated balance sheets. These costs include personnel-related expenses and consultant fees incurred during the application development stages of the project. Costs related to preliminary project activities, minor enhancement and maintenance, and post implementation activities are expensed as incurred. Internal-use software is amortized on a straight-line basis over its useful life, which is generally three years, beginning on the date the software is placed into service. Management evaluates the useful lives of these assets on an annual basis and tests for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets.

During the years ended December 31, 2015, 2014 and 2013, the Company capitalized $2.3 million, $1.2 million, and $1.2 million, respectively, of internal-use software and website development costs. Amortization of internal-use software was $1.1 million, $1.3 million, $1.1 million for the years ended December 31, 2015, 2014 and 2013, respectively.

Patent Assets, Net

The Company generally acquires patent assets from third parties using cash. Patent assets are recorded at fair value at acquisition. The fair value of the assets acquired is generally based on the fair value of the consideration exchanged. The asset value includes the cost of legal and other fees associated with the acquisition of the assets. Costs incurred to maintain and prosecute patents and patent applications are expensed as incurred.

Because each client generally receives a license to the majority of the Company’s patent assets, the Company is unable to reliably determine the pattern over which its patent assets are consumed. As a result, the Company amortizes each patent asset on a straight-line basis. The amortization period is equal to the asset’s estimated economic useful life. Estimating the economic useful life of patent assets requires significant management judgment. The Company considers various factors in estimating the economic useful lives of its patent assets, including the remaining statutory life of the underlying patents, the applicability of the assets to future clients, the vesting period for current clients to obtain perpetual licenses to such patent assets, any contractual commitments by clients that are related to such patent assets, its estimate of the period of time during which the Company may sign subscription agreements with prospective clients that may find relevance in the patent assets, and the remaining contractual term of the Company’s existing clients at the time of acquisition. In certain instances, where the Company acquires patent assets and secures related client committed cash flows that extend beyond the statutory life of the underlying patent assets, the useful life may extend beyond the statutory life of the patent assets. As of December 31, 2015, the estimated economic useful life of the Company’s patent assets generally ranged from 24 to 60 months. The weighted-average estimated economic useful life of patent assets acquired since inception was 44 months. The weighted-average estimated economic useful life of patent assets acquired during the year ended December 31, 2015 was 38 months. The Company periodically evaluates whether events and circumstances have occurred that may warrant a revision to the remaining estimated useful life of its patent assets.

In instances where the Company sells patent assets, the amount of consideration received is compared to the asset’s carrying value to determine and recognize a gain or loss.

Impairment of Long-Lived Assets

The Company assesses the recoverability of its long-lived assets, which includes patent assets, other intangible assets and property and equipment, when events or changes in circumstances indicate their carrying value may not be recoverable. Such events or changes in circumstances may include: a significant adverse change in the extent or manner in which a long-lived asset is being used, a significant adverse change in legal factors or in the business climate that could affect the value of a long-lived asset, an accumulation of costs significantly in excess of the amount originally expected for the acquisition or development of a long-lived asset, current or future operating or cash flow losses that demonstrate continuing losses associated with the use of a long-lived asset or a current expectation that, more-likely-than-not, a long-lived asset will be sold or otherwise disposed of significantly before the end of its previously estimated useful life. The Company licenses a majority of the portfolio of patent assets to all of its membership clients and thus views these assets as a single asset group. The Company assesses recoverability of a long-lived asset by determining whether the carrying value of these assets can be recovered through projected undiscounted cash flows. If the carrying value of the assets exceeds the forecasted undiscounted cash flows, an impairment loss is recognized, and is recorded as the amount by which the carrying value exceeds the estimated fair value. An impairment loss is charged to operations in the period in which management determines such impairment. To date, there have been no impairments of long-lived assets identified.

Goodwill

The Company reviews goodwill for impairment annually on September 30 or more frequently if events or changes in circumstances indicate that the carrying value of goodwill may not be recoverable. For the year ended December 31, 2015, the Company performed the two-step goodwill impairment test for its single reporting unit under ASC Topic 350, Intangibles - Goodwill & Other (“ASC Topic 350”), issued by the FASB. The first step in identifying a potential impairment compares the fair value of the reporting unit with its carrying amount. If the carrying amount exceeds its fair value, the second step would need to be performed; otherwise, no further step is required. The second step, measuring the impairment loss, compares the implied fair value of the reporting unit’s goodwill with the carrying amount of that goodwill. Any excess of the goodwill carrying amount over the implied fair value is recognized as an impairment charge, and the carrying value of goodwill is written down to fair value.

No impairment charges were recorded as a result of the Company’s 2015, 2014, and 2013 annual impairment analyses.

Intangible Assets, Net

Intangible assets, net primarily consists of intangible assets through business combinations. Such assets are capitalized and amortized on a straight-line basis over their estimated useful lives. Intangible assets, net excludes patent related intangible assets, which are recorded within patent assets, net in the consolidated balance sheets.

Advertising Costs

The Company expenses advertising costs as they are incurred. Advertising expenses were not material for any of the periods presented.

Foreign Currency Accounting

The functional currency of the Company’s international subsidiaries is the U.S. dollar. Monetary assets and liabilities are remeasured using the current exchange rate at the balance sheet date. Non-monetary assets and liabilities and capital accounts are reflected using historical exchange rates. Expenses are remeasured using the average exchange rates in effect during the period. Foreign currency exchange gains and losses, which have not been material for any periods presented, are included in the consolidated statements of operations within other income (expense), net.

Income Taxes

The Company accounts for income taxes using an asset and liability approach, which requires the recognition of deferred tax assets or liabilities for the tax-effected temporary differences between the financial reporting and tax bases of its assets and liabilities and for net operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The measurement of deferred tax assets is reduced, if necessary, by the amount of any tax benefits that, based on available evidence, are not expected to be realized.

The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income, and to the extent the Company believes that recovery is not likely, the Company establishes a valuation allowance. Judgment is required in determining the Company’s provision for income taxes, deferred tax assets and liabilities, and any valuation allowance recorded against the net deferred tax assets. The Company applied a $1.1 million valuation allowance against its deferred tax balances at December 31, 2015. The Company did not apply a valuation allowance against its deferred tax balances at December 31, 2014.

The calculation of the Company’s tax liabilities involves dealing with uncertainties in the application of complex tax laws and regulations in a multitude of jurisdictions across its global operations. ASC 740, Income Taxes (“ASC 740”) provides that a tax benefit from an uncertain tax position may be recognized when it is more-likely-than-not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, on the basis of the technical merits. ASC 740 also provides guidance on measurement, derecognition, classification, interest and penalties, accounting in interim periods, disclosure and transition.

The Company recognizes tax liabilities in accordance with ASC 740 and adjusts these liabilities when its judgment changes as a result of the evaluation of new information not previously available. Because of the complexity of some of these uncertainties, the ultimate resolution may result in a payment that is materially different from its current estimate of the tax liabilities. These differences will be reflected as increases or decreases to income tax expense in the period in which new information is available.

The tax expense or benefit for extraordinary items, unusual or infrequently occurring items and items that do not represent a tax effect of current-year ordinary income are treated as discrete items and recorded in the interim period in which the events occur.

Stock-Based Compensation

The Company accounts for stock-based compensation for equity-settled awards issued to employees and directors under ASC 718, Compensation-Stock Compensation (“ASC 718”). ASC 718 requires that stock-based compensation expense for equity-settled awards made to employees and directors be measured based on the estimated grant date fair value and recognized over the requisite service period. These equity-settled awards include stock options, restricted stock units (“RSUs”) and performance-based RSUs which include a service condition, some of which also include a market condition or performance condition (“PBRSUs”).

The fair value of stock options is estimated as of the date of grant using the Black-Scholes option-pricing model. The fair value of RSUs is estimated based on the fair market value of the Company’s common stock on the date of grant. For stock options and RSUs, the fair value of award that is expected to vest is recognized as compensation expense on a straight-line basis over the requisite service period. Because stock-based compensation expense is based on awards ultimately expected to vest, it reflects estimated forfeitures. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from initial estimates. Previously recognized expense is reversed for the portion of awards forfeited prior to vesting.

The fair value of PBRSUs that include performance conditions is estimated by reference to the fair value of the underlying shares on the date of grant. The fair value of PBRSUs that include market conditions is estimated as of the date of grant using the Monte-Carlo simulation model. Stock-based compensation expense for PBRSUs is recognized over the derived service period for each tranche (or market or performance condition). Because the Company’s PBRSUs have multiple derived service periods, it uses the graded-vesting attribution method. The graded vesting attribution method requires a company to recognize compensation expense over the requisite service period for each vesting tranche of the award as though the award were, in substance, multiple awards. The compensation expense for PBRSUs with market conditions will only be reversible if the employee terminates prior to completing the requisite service periods for these awards (i.e., compensation expense will not be reversed if the market condition is not met). For PBRSUs that include performance conditions, the Company only recognizes compensation expense for those awards which vesting is determined to be probable upon satisfaction of certain performance criteria.

Estimates of the fair value of equity-settled awards as of the grant date using valuation models, such as the Black-Scholes option-pricing model and a Monte-Carlo simulation model, are affected by assumptions regarding a number of complex variables. Changes in the assumptions can materially affect the fair value and ultimately how much stock-based compensation expense is recognized. These inputs are subjective and generally require significant analysis and judgment to develop. For all stock options granted to date, the Company calculated the expected term using the SEC simplified method. The Company had limited information on its past volatility and has a limited operating history. Therefore, it had estimated the volatility data based on a study of publicly traded industry peer companies. For purposes of identifying these peer companies, the Company considered the industry, stage of development, size and financial leverage of potential comparable companies. As of the second quarter of 2014, the Company concluded that it had obtained sufficient historical information and, accordingly, ceased use of calculating the expected term using the SEC simplified method and began to calculate its expected term and began using its volatility history. The Company has not granted any stock options since making these changes. The risk-free interest rate is based on the yield available on U.S. Treasury zero-coupon issues similar in duration to the expected term of the equity-settled award.

The Company accounts for stock-based compensation for equity-settled awards issued to non-employees in exchange for goods and services under ASC 505-50, Equity-Based Payments to Non-Employees (“ASC 505-50”). ASC 505-50 requires that equity-settled awards issued to non-employees be measured at the fair value as of the date at which either the commitment for performance by the non-employee to earn the award is reached or the date the non-employee’s performance is complete. Until that point is reached, the award must be revalued at each reporting period with the true-up to expense recorded in the then current period earnings. The value of the award is recognized as an expense over the requisite service period.

Business Combinations

The Company applies the provisions of ASC 805, Business Combinations (“ASC 805”), in the accounting for its business acquisitions. ASC 805 requires companies to recognize goodwill separately from the assets acquired and liabilities assumed, which are valued at their acquisition date fair values. Goodwill as of the acquisition date represents the excess of the purchase price over the fair values of the assets acquired and the liabilities assumed.

The Company uses significant estimates and assumptions, including fair value estimates, to determine fair value of assets acquired, liabilities assumed and, when applicable, the related useful lives of the acquired assets, as of the business combination date. When those estimates are provisional, the Company refines them as necessary during the measurement period. The measurement period is the period after the acquisition date, not to exceed one year, in which the Company may gather new information about facts and circumstances that existed as of the acquisition date to adjust the provisional amounts recognized. Measurement period adjustments are applied retrospectively. All other adjustments are recorded in the consolidated statements of operations.

Reserves for Known and Incurred but not Reported Claims

Reserves for known and incurred but not reported claims represent estimated claims costs and related expenses for patent infringement liability insurance policies in effect. Reserves for known claims are established based on individual case estimates. The Company uses actuarial models and techniques to estimate the reserve for incurred but not reported claims.

Loss expense for known and incurred but not reported claims are charged to earnings after deducting recoverable amounts under our reinsurance contract. Loss expense for known and incurred but not reported claims associated with policies that the Company issued on behalf of a Lloyd's of London underwriting syndicate are charged to earnings for the portion of the underwriting risk that the Company assumes.

Recent Accounting Pronouncements

In November 2015, the FASB issued Accounting Standards Update ("ASU") No. 2015-17, Balance Sheet Classification of Deferred Taxes, requiring all deferred tax assets and liabilities, and any related valuation allowance, to be classified as non-current on the balance sheet. The classification change for all deferred taxes as non-current simplifies entities’ processes as it eliminates the need to separately identify the net current and net non-current deferred tax asset or liability in each jurisdiction and allocate valuation allowances. The Company elected to prospectively adopt the accounting standard in the beginning of our fourth quarter of 2015. Prior periods in our consolidated financial statements were not retrospectively adjusted.

In September 2015, the FASB issued ASU 2015-16, Simplifying the Accounting for Measurement-Period Adjustments guidance to simplify the accounting for adjustments made during the measurement period to provisional amounts recognized in a business combination. This guidance is effective for fiscal years and interim periods beginning after December 15, 2015, and requires prospective application. Early adoption is permitted. The Company expects to adopt this guidance when effective, and does not expect this guidance to have a significant impact on its consolidated financial statements.

In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU 2014-09”), which will supersede most existing revenue recognition guidance in U.S. generally accepted accounting principles (“U.S. GAAP”) once it becomes effective. ASU 2014-09 requires an entity to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration that is expected to be received for those goods or services. ASU 2014-09 defines a five-step process to achieve this core principle and, in doing so, it is possible more judgment and estimates may be required within the revenue recognition process than is currently required under existing U.S. GAAP including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. ASU 2014-09 will be effective for annual and interim periods beginning after December 15, 2017 and early adoption is permitted for annual and interim periods beginning after December 15, 2016. The Company is currently evaluating the impact of the adoption of ASU 2014-09 on its consolidated financial statements.

Net Income Available to Common Stockholders

12 Months Ended

Dec. 31, 2015

Net Income Available to Common Stockholders

Net Income Available to Common Stockholders

Basic and diluted net income per share available to common stockholders are presented in conformity with the two-class method required for participating securities. Under the two-class method, basic net income per share available to common stockholders is computed by dividing the net income available to common stockholders by the weighted-average number of shares of common stock outstanding during the period. Diluted net income per share available to common stockholders is computed by using the weighted-average number of shares of common stock outstanding, including potential dilutive shares of common stock, assuming the dilutive effect of outstanding stock options and restricted stock units using the treasury stock method.

The following table presents the calculation of basic and diluted net income per share available to common stockholders (in thousands, except for per share data):



	Year Ended December 31,
	2015		2014		2013
Net income available to common stockholders:
Numerator:
Net income	$	39,422	$	39,341	$	40,783
Allocation of net income to participating stockholders	—		—		(20		)
Net income available to common stockholders	$	39,422	$	39,341	$	40,763
Denominator:
Basic shares:
Weighted-average shares used in computing basic net income available to common stockholders	54,432		53,444		51,956
Diluted shares:
Weighted-average shares used in computing basic net income available to common stockholders	54,432		53,444		51,956
Dilutive effect of stock options and restricted stock units using treasury-stock method	978		1,374		1,696
Weighted-average shares used in computing diluted net income available to common stockholders	55,410		54,818		53,652
Net income per common share available to common stockholders:
Basic	$	0.72	$	0.74	$	0.78
Diluted	$	0.71	$	0.72	$	0.76

For the years ended December 31, 2015, 2014 and 2013 the following securities were not included in the calculation of diluted shares outstanding, as the effect would have been anti-dilutive (in thousands):



	Year Ended December 31,
	2015	2014	2013
Weighted-average:
Stock options outstanding	663	767	1,215
Restricted stock units outstanding	263	100	127
Shares of common stock subject to repurchase	—	—	25

Financial Instruments

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

Financial Instruments

The following tables present the Company's financial assets and liabilities measured at fair value on a recurring basis (in thousands):



	December 31, 2015
	Amortized Cost		Unrealized					Estimated Fair Value		Level 1		Level 2		Level 3
	Amortized Cost		Gains		Losses			Estimated Fair Value		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
Commercial paper	$	7,997	$	—	$	—		$	7,997	$	—	$	7,997	$	—
Municipal bonds	1,635		—		—			1,635		—		1,635		—
Money market funds	54,663		—		—			54,663		54,663		—		—
	$	64,295	$	—	$	—		$	64,295	$	54,663	$	9,632	$	—
Short-term investments:
Municipal bonds	$	133,033	$	—	$	(96	)	132,937		$	—	$	132,937	$	—
Commercial paper	5,493		—		(3		)	5,490		—		5,490		—
Corporate bonds	30,488		3		(93		)	30,398		—		30,398		—
U.S. government and agency securities	61,559		—		(62		)	61,497		—		61,497		—
Equity securities	123		—		—			123		123		—		—
	$	230,696	$	3	$	(254	)	$	230,445	$	123	$	230,322	$	—
Liabilities:
Current liabilities:
Deferred payment obligations	$	6,270	$	3,887	$	—		$	2,383	$	—	$	—	$	2,383



	December 31, 2014
	Amortized Cost		Unrealized					Estimated Fair Value		Level 1		Level 2		Level 3
	Amortized Cost		Gains		Losses			Estimated Fair Value		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
Commercial paper	$	5,749	$	—	$	—		$	5,749	$	—	$	5,749	$	—
U.S. government and agency securities	2,000		—		—			2,000		—		2,000		—
Municipal bonds	1,409		—		—			1,409		—		1,409		—
Money market funds	451		—		—			451		451		—		—
	$	9,609	$	—	$	—		$	9,609	$	451	$	9,158	$	—
Short-term investments:
Municipal bonds	$	120,270	$	24	$	(12	)	$	120,282	$	—	$	120,282	$	—
Commercial paper	2,498		—		—			2,498		—		2,498		—
Corporate bonds	68,758		1		(87		)	68,672		—		68,672		—
U.S. government and agency securities	48,095		—		(33		)	48,062		—		48,062		—
	$	239,621	$	25	$	(132	)	$	239,514	$	—	$	239,514	$	—

The Company's short-term investments are generally classified as available-for-sale. Available-for-sale investments are reported at fair value, with unrealized gains and losses, net of tax, included as a separate component of stockholders’ equity within accumulated other comprehensive income (loss). During the years ended December 31, 2015 and 2014, the Company realized losses on the sales and exchanges of short-term investments of $3.4 million and nil, respectively, and other-than-temporary impairments on its short-term investments of $5.1 million and nil, respectively, which are included in the consolidated statements of operations within other income (expense), net.

As of December 31, 2015 and 2014, approximately 87% and 76%, respectively, of our marketable security investments mature within one year and 13% and 24%, respectively, mature within one to five years. As of December 31, 2015, no individual securities incurred continuous unrealized losses for greater than 12 months.

As of December 31, 2015 and 2014, the Company had short-term cost method investments of $0.6 million and nil, respectively. Cost method investments are recorded at amortized cost in short-term investments in the Company's consolidated balance sheets.

In connection with the Rockstar Transaction (see Note 10, "Commitments and Contingencies"), the Company received funding of $6.3 million from a syndicate participant. At December 31, 2015, the fair value of the loan from the syndicate participant was $2.4 million and was categorized as Level 3.

Level 3 Valuation Techniques

Level 3 financial liabilities consist of repayment obligations to a third party for which determination of fair value requires significant judgment and estimation. Changes in fair value measurement categorized within Level 3 of the fair value hierarchy are analyzed each period for changes in estimates or assumptions and recorded as the Company deems appropriate.

The Company uses the Black-Scholes option valuation model to value these deferred payment obligations at inception and subsequent valuation dates. This model incorporates assumptions about details such as the value of underlying investments, expected terms, maturity, risk-free interest rates, as well as volatility. A significant change in volatility and expected term could result in a significant change in fair value. The risk-free interest rate was based on the implied yield currently available on U.S. Treasury zero coupon issues with an equivalent remaining term at the measurement date. The expected volatility was calculated using the standard deviation of the underlying security's weekly returns over the estimated period of time to take to settle the liability. The expected term of the liability is determined by the estimated settlement date of the liability. Changes in the fair value are recorded in other income (expense), net in the Company's consolidated statements of operations. As of December 31, 2015, there were no transfers in or out of Level 3 from other levels of the fair value hierarchy.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Patent Assets, Net

12 Months Ended

Dec. 31, 2015

Patent Assets [Abstract]

Patent Assets, Net

Patent assets, net consisted of the following (in thousands):



	December 31, 2014			Additions			Sales			December 31, 2015
Patent assets	$	665,290		$	160,664		$	(1,696	)	$	824,258
Accumulated amortization	(428,941		)	(142,296		)	1,539			(569,698		)
Patent assets, net	$	236,349								$	254,560



	December 31, 2013			Additions			Sales			December 31, 2014
Patent assets	$	529,526		$	136,468		$	(704	)	$	665,290
Accumulated amortization	(309,572		)	(119,694		)	325			(428,941		)
Patent assets, net	$	219,954								$	236,349

The Company’s acquired patent assets relate to technologies used or supplied by companies in a variety of market sectors, including consumer electronics, e-commerce, financial services, media distribution, mobile communications, networking, semiconductors, and software. The Company amortizes each acquired portfolio of patent assets on a straight-line basis over its estimated economic useful life. As of December 31, 2015, the estimated economic useful lives of the Company’s patent assets generally ranged from 24 to 60 months with a weighted-average estimated economic useful life at the time of acquisition of 44 months.

As of December 31, 2015, the Company expects amortization expense in future periods to be as follows (in thousands):



2016	$	136,322
2017	74,725
2018	25,841
2019	14,662
2020	3,010
Total estimated future amortization expense	$	254,560

Amortization expense was $142.4 million, $119.7 million and $105.5 million for the years ended December 31, 2015, 2014 and 2013, respectively.

Syndicated Acquisitions

Syndicated acquisitions are transactions involving patent assets that may cost more than the Company is prepared to spend with its own capital resources or that are relevant only to a limited number of clients. In such transactions, the Company may work to acquire these assets with financial assistance from the particular clients against whom they are being or may be asserted. Such clients either pay amounts separate from their subscription fee or, less frequently, lend the Company funds to be used in the transaction. As discussed in the revenue recognition policy in Note 2, the Company may treat the contributions from such clients as revenue on a gross or net basis depending on the specific facts and circumstances of the transaction. In the event that such contributions are recognized on a net basis, the Company will only capitalize the acquired asset that relates to its non-contributing clients. As a result, in such situations the cost basis of the acquired patent rights excludes the amounts paid by the contributing clients.

On December 22, 2014, the Company and RPX Clearinghouse LLC (a wholly-owned subsidiary of the Company) entered into an Asset Purchase Agreement by and among Rockstar Consortium US LP, Rockstar Consortium LLC, Bockstar Technologies LLC, Constellation Technologies LLC, MobileStar Technologies LLC, and NetStar Technologies LLC (the “Sellers”), for the purchase of substantially all of the patent assets owned or controlled by the Sellers (the “Rockstar Transaction”), as well as other ancillary agreements, including but not limited to an Escrow Agreement by and among the Sellers, Citibank, N.A., acting as escrow agent, RPX Clearinghouse LLC and the Company (the “Escrow Agreement”). Upon the closing of the Rockstar Transaction, syndicate participants received non-exclusive licenses to the patent assets included in the Rockstar Transaction, and RPX Clearinghouse made the patent assets available for license to all other interested companies under fair, reasonable, and non-discriminatory terms. On December 26, 2014, upon the execution of the Escrow Agreement and the Agreement, RPX Clearinghouse LLC paid the Sellers $25.0 million as a non-refundable deposit. The third-party funding commitments, as described below, were derived pursuant with the Escrow Agreement and the remaining closing conditions under the Asset Purchase Agreement were met on January 28, 2015 on which date the Rockstar Transaction was consummated and the Sellers received an additional payment of $875.0 million from escrow.

RPX Clearinghouse LLC received funding commitments for the Rockstar Transaction from a syndicate of more than 30 companies. The Company evaluated the contributions from syndicate members to determine whether they should be recorded on a gross or net basis. As a result, the Company accounted for these third-party funding commitments on a net basis as it acted as an agent to acquire patent rights from the Sellers on behalf of the syndicate who paid for such rights separately from a subscription agreement. The Company contributed approximately $29.0 million which was recorded as a patent asset upon closing of the Rockstar Transaction and is amortized over its estimated economic useful life of 60 months.

Property and Equipment, Net

12 Months Ended

Dec. 31, 2015

Property and Equipment, Net

Property and Equipment, Net

operty and Equipment, Net

Property and equipment, net, consisted of the following (in thousands):



	December 31,
	2015			2014
Internal-use software	$	7,654		$	5,358
Leasehold improvements	1,799			1,799
Computer, equipment and software	1,387			1,221
Furniture and fixtures	818			818
Construction-in-progress	—			167
Total property and equipment, gross	11,658			9,363
Less: Accumulated depreciation and amortization	(6,925		)	(5,212		)
Total property and equipment, net	$	4,733		$	4,151

Depreciation and amortization expense was $1.7 million, $2.0 million and $1.6 million for the years ended December 31, 2015, 2014 and 2013, respectively. Stock-based compensation capitalized as part of the cost of internal-use software was $0.1 million for each year ended December 31, 2015, 2014 and 2013, respectively.

Intangible Assets, Net

12 Months Ended

Dec. 31, 2015

Intangible Assets, Net

Intangible Assets, Net

Intangible assets, net, as of December 31, 2015 and 2014 consisted of the following (in thousands except years):



		December 31, 2015							December 31, 2014
	Weighted-Average Life Remaining (years)	Carrying Amount		Accumulated Amortization			Net Carrying Amount		Carrying Amount		Accumulated Amortization			Net Carrying Amount
Proprietary data and models	3.8	$	2,100	$	(1,694	)	$	406	$	2,100	$	(1,119	)	$	981
Trademarks	3.6	1,720		(1,645		)	75		1,890		(1,565		)	325
Developed technology	2.6	120		(120		)	—		433		(433		)	—
Customer relationships	3.0	1,050		(659		)	391		1,050		(392		)	658
Covenant not to compete	3.0	1,900		(971		)	929		1,920		(358		)	1,562
		$	6,890	$	(5,089	)	$	1,801	$	7,393	$	(3,867	)	$	3,526

As of December 31, 2015, the Company expects amortization expense in future periods to be as follows (in thousands):



2016	$	1,288
2017	513
Total estimated future amortization expense	$	1,801

Amortization expense related to intangible assets was $1.7 million, $1.5 million, and $1.5 million for the years ended December 31, 2015, 2014 and 2013, respectively.

Commitments and Contingencies

12 Months Ended

Dec. 31, 2015

Commitments and Contingencies Disclosure [Abstract]

Commitments And Contingencies

Commitments and Contingencies

Operating Lease Commitments

The Company leases its facilities under non-cancelable lease agreements. Certain of these arrangements have free rent, escalating rent payment provisions and tenant allowances. Under such arrangements the Company recognizes rent expense on a straight line basis over the non-cancelable lease term and records the difference between cash rent payments and the recognition of rent expense as a deferred rent liability within other current liabilities and other liabilities for the current and non-current portion, respectively, in the Company's consolidated balance sheets.

In March 2012, the Company entered into an amended lease agreement related to its San Francisco, California office space. The amendment, which took effect on May 1, 2013, increased the rentable space to approximately 67,000 total square feet and extended the term through October 2019. The monthly base rent payments pursuant to this lease are approximately $0.3 million per month, increasing to approximately $0.4 million per month over the life of the lease.

In October 2013, the Company entered into an agreement to sublease a portion of its San Francisco, California office space. This sublease took effect on February 1, 2014 for a 36-month term through January 2017. The Company received income from this sublease of $0.6 million for the year ended December 31, 2015.

Rent expense related to non-cancelable operating leases, net of sublease income, was $3.5 million in each year ended December 31, 2015, 2014 and 2013, respectively.

As of December 31, 2015, the future minimum lease payments required under non-cancelable operating leases and the future minimum payments to be received from non-cancelable subleases were as follows:



2016	$	4,284
2017	4,206
2018	4,273
2019	3,613
Future non-cancelable minimum operating lease payments	16,376
Less: minimum payments to be received from non-cancelable subleases	(787		)
Total future non-cancelable minimum operating lease payments, net	$	15,589

Deferred Payment Obligations

In connection with the Rockstar Transaction (see Note 5, "Patent Assets, Net"), the Company acquired certain common stock, convertible preferred stock, and redeemable convertible preferred stock investments held by the Sellers. To fund the acquisition of these investments, the Company received $6.3 million from a syndicate participant and seller financing of $5.9 million. These balances were considered loans in the Company's consolidated balance sheets and were recorded as deferred payment obligations under current liabilities as they were expected to be repaid within 12 months.

The loan received from the syndicate participant bears no interest. The terms of the obligation require repayment up to the $6.3 million received only to the extent proceeds are received from the sale of the common and convertible preferred stock securities, which resulted in a difference between the funding received and the fair value of the loan. The Company elected to carry this loan at fair value and has categorized it as a Level 3 instrument due to the significance of unobservable inputs developed using company-specific information to estimate the loan’s fair value. Changes in fair value are reported in other income (expense), net in the Company's consolidated statements of operations. During the year ended December 31, 2015, the fair value of this loan decreased from $6.3 million to $2.4 million, resulting in a gain of $3.9 million recognized in other income (expense), net in the consolidated statements of operations.

The loan received from the Sellers was carried at cost, bore no interest, and was repayable upon redemption or conversion of the redeemable convertible preferred stock. During the year ended December 31, 2015, the Company paid $0.9 million and later fully settled the seller financing contingent on the consummation of a nonmonetary transaction whereby the Sellers agreed to settle its remaining $5.0 million loan for $2.0 million which resulted in a gain on extinguishment of $3.0 million. The Company also transferred equity securities in this nonmonetary transaction with a carrying value of $5.5 million in exchange for patent assets which resulted in a loss recognized on the exchange of $3.3 million. The gain on extinguishment and loss on transfer of equity securities were recognized in other income (expense), net in the consolidated statements of operations.

Litigation

From time to time, the Company may be a party to various litigation claims in the normal course of business. Legal fees and other costs associated with such actions are expensed as incurred. The Company assesses, in conjunction with its legal counsel, the need to record a liability for litigation or contingencies. A liability is recorded when and if it is determined that such a liability for litigation or contingencies is both probable and reasonably estimable. No liability for legal contingencies was recorded as of December 31, 2015 or 2014.

In June 2013, Kevin O’Halloran, as Trustee of the Liquidating Trust of Teltronics, Inc. (the “Debtor”), filed a complaint in the U.S. Bankruptcy Court for the Middle District of Florida against the Company and Harris Corporation (the “Defendants”). The complaint alleges that the Defendants are liable under federal and state bankruptcy law regarding fraudulent transfers for the value of a patent portfolio purchased by the Company from Harris Corporation pursuant to an agreement entered into in January 2009, and within four years of the date the Debtor filed its petition in bankruptcy. In February 2015, the Court held a trial and in November 2015 entered judgment in favor of the Defendants. In December 2015, the Debtor filed an appeal of the judgment. The Company is not currently able to determine whether there is a reasonable possibility that a loss has been incurred, nor can it estimate the potential loss or range of the potential loss that may result from this litigation.

In March 2012, Cascades Computer Innovations LLC filed a complaint in U.S. District Court for the Northern District of California (the “Court”) against the Company and five of its clients (collectively the “Defendants”). The complaint alleges that the Defendants violated federal antitrust law, California antitrust law and California unfair competition law. The complaint further alleges that after the Company terminated its negotiations with the plaintiff to license certain patents held by the plaintiff, the Defendants violated the law by jointly refusing to negotiate or accept licenses under the plaintiff’s patents. The plaintiff seeks unspecified monetary damages and injunctive relief. In January 2013, the Court dismissed the complaint against the Defendants and granted the plaintiff leave to amend its complaint. In February 2013, the plaintiff filed an amended lawsuit alleging that the Defendants violated federal antitrust law, California antitrust law and California unfair competition law. In February 2016, the Court entered judgment in favor of the Defendants on the federal antitrust claims, and requested further briefing by the parties on the remaining state law claims. The Company is not currently able to determine whether there is a reasonable possibility that a loss has been incurred, nor can it estimate the potential loss or range of the potential loss that may result from this litigation.

Guarantees and Indemnifications

The Company has, in connection with the sale of patent assets, agreed to indemnify and hold harmless the buyer of such patent assets for losses resulting from breaches of representations and warranties made by the Company. The terms of these indemnification agreements are generally perpetual. The maximum amount of potential future indemnification is unlimited. To date, the Company has not paid any amount to settle claims or defend lawsuits. The Company is unable to reasonably estimate the maximum amount that could be payable under these arrangements since these obligations are not capped but are conditional to the unique facts and circumstances involved. Accordingly, the Company had no liabilities recorded for these agreements as of December 31, 2015 or 2014. The Company has no reason to believe that there is any material liability related to such indemnification provisions. The Company does not indemnify its clients for patent infringement.

In accordance with its amended and restated bylaws, the Company also indemnifies certain officers and employees for losses incurred in connection with actions, suits or proceedings threatened or brought against such officer or employee arising from his or her service to the Company as an officer or employee, subject to certain limitations. The term of the indemnification period is indefinite. The maximum amount of potential future indemnification is unspecified. The Company has no reason to believe that there is any material liability for actions, events or occurrences that have occurred to date.

Reserves for Known and Incurred but not Reported Claims

In August 2012, the Company began offering insurance to cover certain costs of litigation brought against its insured clients by NPEs. As of December 31, 2015 and 2014, the Company had a total of 89 and 48 active policies, respectively, and has recorded a reserve of $0.7 million and $0.5 million, respectively, for known and incurred but not reported claims that represent estimated claim costs and related expenses.

The Company regularly reviews loss reserves using a variety of actuarial techniques and updates them as its loss experience develops.

Stock-Based Compensation

12 Months Ended

Dec. 31, 2015

Stock-Based Compensation

Stockholder's Equity

Common Stock

As of December 31, 2015, under the Company’s amended and restated certificate of incorporation, the Company is authorized to issue 200 million shares of common stock with a par value of $0.0001 per share.

Preferred Stock

As of December 31, 2015, under the Company’s amended and restated certificate of incorporation, the Company is authorized to issue 10 million shares of preferred stock with a par value of $0.0001 per share. The Board of Directors is authorized to provide for the issuance of one or more series of preferred stock and to establish the powers, preferences and rights of the preferred shares.

Equity Plans

In February 2011, the Company’s Board of Directors adopted the 2011 Equity Incentive Plan (the “2011 Plan”), which became effective on the date of the Company’s initial public offering. The 2011 Plan provides for the issuance of incentive stock options, non-qualified stock options, stock appreciation rights, restricted shares of the Company’s common stock and stock units to employees, directors and non-employees. The Board of Directors initially reserved 1,500,000 shares of common stock for future issuance under the 2011 Plan. In March 2015 and 2014, the Company reserved an additional 1,000,000 shares of common stock each year for future issuance under the 2011 Plan. As of December 31, 2015, there were 3,093,605 shares available for grant under the 2011 Plan.

In August 2008, the Company’s Board of Directors adopted the 2008 Plan (the “2008 Plan”) which provided for the issuance of incentive stock options, non-qualified stock options, as well as the direct award or sale of shares of common stock to employees, directors and non-employees for up to 9,019,474 shares of common stock, as amended. No further awards have been made under the 2008 Plan since the 2011 plan became effective; however, all awards outstanding under the 2008 Plan will continue to be governed by the existing terms.

Under both the 2011 Plan and 2008 Plan, incentive stock options and non-qualified stock options are to be granted at a price that is not less than 100% of the fair value of the stock at the date of grant. Stock options granted to newly hired employees vest 25% on the first anniversary of the date of hire and ratably each month over the ensuing 36-month period. Stock options granted to existing employees generally vest ratably over the 48-months following the date of grant. Stock options are exercisable for a maximum period of 10 years after date of grant. Incentive stock options granted to stockholders who own more than 10% of the outstanding stock of the Company at the time of grant must be issued at an exercise price not to be less than 110% of the fair value of the stock on the date of grant. RSUs granted to newly hired employees vest 25% on the first Company-established vest date after the first anniversary of the employee’s date of hire and ratably each quarter over the ensuing 12-quarter period. RSUs granted to existing employees generally vest ratably each quarter over the 16 quarters following the date of grant. PBRSUs with market conditions granted to employees may vest 25% on each anniversary of the grant date, provided that the average closing price per share of the Company’s common stock for any 90-calendar day period during the year preceding such anniversary date is equal to or greater than 1.25 times the Company’s stock price on the grant date or on the anniversary of the grant date. To the extent that a portion of the award does not vest on a specific anniversary date, it will remain eligible to vest in any of following three successive anniversaries of the grant date, provided that any applicable market conditions have been satisfied at that time. PBRSUs with performance conditions granted to employees generally vest 25% annually if the performance criteria is satisfied.

A summary of the Company’s activity under its equity-settled award plans and related information is as follows (in thousands, except per share data):



			Options Outstanding
	Shares Available for Grant		Number of Shares		Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Life in Years	Aggregate Intrinsic Value
Balance - December 31, 2014	2,685		3,264		$	10.38
Shares authorized	1,000		—		—
Options exercised	—		(778	)	6.44
Options forfeited	146		(146	)	19.63
Restricted stock units granted	(1,433	)	—		—
Restricted stock units forfeited	407		—		—
Restricted stock units withheld related to net share settlement of restricted stock units	354		—		—
Balance - December 31, 2015	3,159		2,340		11.11		5.2	$	4,430
Vested and exercisable - December 31, 2015			2,093		11.44		5.2	3,739
Vested and expected to vest - December 31, 2015			2,327		11.13		5.2	4,390

The aggregate intrinsic value of stock options exercised during the years ended December 31, 2015, 2014 and 2013 was $6.8 million, $7.0 million and $13.5 million, respectively. The total fair value of stock options vested during the years ended December 31, 2015, 2014 and 2013 was $3.3 million, $6.2 million and $9.1 million, respectively.

Restricted Stock Units

The summary of restricted stock unit activity, which includes PBRSUs, is as follows (in thousands, except for per share data):



	Number of Shares		Weighted-Average Grant Date Fair Value		Aggregate Intrinsic Value
Non-vested units - December 31, 2014	2,460		$	13.15
Granted	1,433		14.09
Vested	(996	)	14.00
Forfeited	(407	)	13.29
Non-vested units - December 31, 2015	2,490		13.35		$	28,109

The total fair value of RSUs vested during the years ended December 31, 2015, 2014 and 2013 was $14.4 million, $13.7 million and $6.6 million, respectively.

In October 2013, the Board of Directors approved net-share settlement for tax withholdings on RSU vesting. In 2015 and 2014, the Company withheld issuing 354,446 and 325,292 shares of its common stock, respectively, based on the value of the RSUs on their vesting dates as determined by the Company’s closing common stock price. Total payments for the employees’ minimum tax obligations to taxing authorities were $5.1 million and $4.9 million for the years ended December 31, 2015 and 2014, respectively, and were recorded as a reduction to additional paid-in capital and reflected as a financing activity within the consolidated statements of cash flows. The net-share settlements reduced the number of shares that would have otherwise been issued on the vesting date and increased the number of shares reserved for future issuance under the 2011 Plan.

Stock-Based Compensation Related to Employees and Directors

The Company estimates the fair value of stock options using the Black-Scholes option pricing model. The Company did not grant stock options during the years ended December 31, 2015 or 2014. The weighted-average assumptions used to estimate the fair value of stock options granted and the resulting fair value is as follows:



	Year Ended December 31,
	2013
Dividend yield	—		%
Risk-free rate	0.93		%
Expected volatility	61		%
Expected term (in years)	6.1
Grant date fair value	$	7.39

The fair value of RSUs granted to employees and non-employee directors is measured by reference to the fair value of the underlying shares on the date of grant.

PBRSUs granted during the year ended December 31, 2015 contain both service and performance conditions that affect the quantity of awards that will vest. PBRSUs granted during the years ended December 31, 2014 and 2013 contain both service and market conditions that affect the quantity of awards that will vest. During the years ended December 31, 2015, 2014, and 2013, the Company granted 54,375, 200,000, and 175,000 PBRSUs, respectively. The Company estimates the grant date fair value of PBRSUs which include performance conditions by reference to the fair value of the underlying shares on the date of grant. The Company estimates the grant date fair value of PBRSUs which include market conditions using the Monte Carlo simulation model which are only applicable for the years ended December 31, 2014 and 2013. The weighted-average assumptions used to estimate the fair value of PBRSUs with market conditions and the resulting fair values are as follows:



	Year Ended December 31,
	2014			2013
Dividend yield	—			—
Risk free rate	1.11		%	0.59		%
Expected volatility	48		%	53		%
Grant date fair value	$	7.47		$	6.39

Stock-based compensation expense related to stock options granted to employees and non-employee directors was $2.9 million, $5.4 million and $8.5 million for the years ended December 31, 2015, 2014 and 2013, respectively. Stock-based compensation expense related to RSUs granted to employees and non-employee directors was $14.2 million, $11.6 million and $6.9 million for the years ended December 31, 2015, 2014 and 2013, respectively. Stock-based compensation expense related to PBRSUs granted to employees was $0.7 million, $0.8 million, and $0.4 million for the years ended December 31, 2015, 2014 and 2013, respectively.

As of December 31, 2015, there was $1.1 million and $30.2 million of unrecognized compensation cost related to stock options and RSUs, including PBRSUs, respectively, which is expected to be recognized over a weighted-average period of 0.6 years and 2.4 years, respectively. Future grants of equity awards will increase the amount of stock-based compensation expense to be recorded.

Stock-Based Compensation Related to Non-Employees

Stock-based compensation expense for non-employees is based on the fair value of the award on the measurement date, which is the earlier of the date by which the commitment for performance by the non-employee to earn the award is reached and the date on which the non-employee’s performance is complete. Each reporting period, the fair value of the unvested non-employee options or restricted stock units is revalued until the awards vest on the measurement date.

Non-employee stock-based compensation expense related to stock options was nil, nil and $0.2 million for the years ended December 31, 2015, 2014 and 2013, respectively. Non-employee stock-based compensation expense related to RSUs was nil, nil and $0.2 million for the years ended December 31, 2015, 2014 and 2013, respectively.

Stock Repurchase Program

On February 10, 2015, the Company announced that its Board of Directors had authorized a share repurchase program under which the Company is authorized to repurchase up to $75.0 million of its outstanding common stock with no expiration date from the date of authorization. As of December 31, 2015, the Company repurchased $26.2 million of the outstanding common stock. Under the program, shares may be purchased in open market transactions, including through block purchases, through privately negotiated transactions, or pursuant to any trading plan that may be adopted in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"). The share repurchase program does not have an expiration date and may be suspended, terminated or modified at any time for any reason. The Company’s share repurchase program does not obligate it to acquire any specific number of shares. The Company repurchased shares of its common stock in the open market, which were retired upon repurchase. The purchase price for the repurchased shares are reflected as a reduction to common stock and retained earnings in the Company's condensed consolidated balance sheet during the period presented as follows (in thousands, except per share data):



	Shares Repurchased	Average Price per Share		Value of Shares Repurchased
Cumulative shares repurchased as of January 1, 2015	—	$	—	$	—
Repurchase of shares of common stock	1,993	13.12		26,175
Cumulative shares repurchased as of December 31, 2015	1,993	$	13.12	$	26,175

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(d),(e))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21484-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 4.E)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21488-112644

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29-31)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-Subparagraph (SAB TOPIC 4.C)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Topic 505
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
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-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6405834&loc=d3e23285-112656

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Preferred Stock
-URI http://asc.fasb.org/extlink&oid=6521494

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21564-112644

Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section E

Reference 15: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section C

+ Details

Income Taxes

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Income Taxes

Income before income tax provision consists of the following (in thousands):



	Year Ended December 31,
	2015		2014		2013
Domestic	$	65,445	$	64,238	$	64,281
International	54		44		14
Total income before provision for income taxes	$	65,499	$	64,282	$	64,295

The components of the provision for income taxes are as follows (in thousands):



	Year Ended December 31,
	2015			2014			2013
Current:
Federal	$	(23,456	)	$	(26,517	)	$	(17,145	)
State	(2,790		)	(3,031		)	(1,188		)
Foreign	(12,406		)	(9,611		)	(8,220		)
Total current provision for income taxes	(38,652		)	(39,159		)	(26,553		)
Deferred:
Federal	12,022			13,668			2,920
State	553			550			121
Total deferred benefit for income taxes	12,575			14,218			3,041
Total provision for income taxes	$	(26,077	)	$	(24,941	)	$	(23,512	)

Net deferred tax assets (liabilities) consist of the following (in thousands):



	December 31,
	2015			2014
Deferred tax assets:
Deferred revenue	$	1,438		$	2,779
Reserves and other	5,017			2,319
Stock-based compensation	5,701			5,963
Depreciation and amortization	5,560			—
Total deferred tax assets	17,716			11,061
Valuation allowance	(1,097		)	—
Net deferred tax assets	16,619			11,061

Deferred tax liabilities:
Depreciation and amortization	—			(6,568		)
Net deferred tax liabilities	—			(6,568		)

Net deferred taxes	$	16,619		$	4,493

The following is a reconciliation of the statutory federal income tax to the Company’s effective tax (in thousands):



	Year Ended December 31,
	2015			2014			2013
Tax at statutory federal rate	$	(22,939	)	$	(22,498	)	$	(22,503	)
State tax – net of federal benefit	(1,459		)	(1,678		)	(655		)
Permanent differences	(663		)	(879		)	(569		)
Foreign tax	(12,370		)	(9,576		)	(8,214		)
Foreign tax credits	12,370			9,576			8,216
Foreign income not taxed at federal rate	(3		)	(3		)	1
Change in valuation allowance	(1,097		)	—			—
Other	84			117			212
Total provision for income taxes	$	(26,077	)	$	(24,941	)	$	(23,512	)

As of December 31, 2015, the Company had federal and state capital loss carryforwards of $3.3 million available to reduce future taxable income which expire in 2020 if not utilized.

In assessing the realization of deferred tax assets, management considers whether it is more-likely-than-not that some portion or all of deferred assets will not be realized. The ultimate realization of the deferred tax asset is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Based on the available objective evidence as of December 31, 2015, management believes it is more-likely-than-not that the U.S. net deferred tax asset, other than certain capital losses, will be fully realized. The Company recorded a valuation allowance of $1.1 million during the year ended December 31, 2015 due to the addition of current year capital loss carryforwards.

Deferred tax liabilities have not been recognized for undistributed earnings for foreign subsidiaries because it is management’s intention to indefinitely reinvest such undistributed earnings outside the U.S. Generally, such earnings are subject to potential foreign withholding tax and the U.S. tax upon remittance of dividends and under certain other circumstances. The Company believes that the potential liability would not be material.

In November 2015, the FASB issued ASU 2015-17, Balance Sheet Classification of Deferred Taxes, related to balance sheet classification of deferred taxes which requires deferred tax assets and liabilities to be classified as non-current in the Company's consolidated balance sheets, thereby simplifying the current guidance which requires an entity to separate deferred assets and liabilities into current and non-current amounts. The Company early adopted this ASU in the beginning of the fourth quarter of 2015 on a prospective basis and its consolidated balance sheets as of this date reflect the revised classification. The impact to the Company's consolidated balance sheets is a reclassification from current to non-current deferred tax assets of $4.4 million.

Uncertain Tax Positions

As of December 31, 2015, the Company’s total amount of unrecognized tax benefits was $5.3 million, all of which would impact the Company’s effective tax rate, if recognized.

The following table summarizes the activity related to the Company’s unrecognized tax benefits (in thousands):



	2015		2014			2013
Balance as of January 1,	$	3,707	$	2,036		$	1,136
Gross increase related to current period tax positions	1,606		1,672			1,043
Gross increase (decrease) related to prior period tax positions	2		(1		)	(143		)
Balance as of December 31,	$	5,315	$	3,707		$	2,036

The Company does not believe it is reasonably possible that its unrecognized tax benefits will materially change within the next twelve months.

The Company’s policy is to recognize interest and penalties accrued on any unrecognized tax benefits as a component of income tax expense. During the years ended December 31, 2015, 2014 and 2013, the Company recognized $0.4 million, $0.7 million, and $0.1 million, respectively, of interest and penalties associated with unrecognized tax benefits.

During 2015, the statute of limitations expired with respect to the Company’s 2010 tax year which was under examination by the State of California Franchise Tax Board. The conclusion of this examination did not have a material impact on the Company's consolidated financial statements. The 2012 through 2015 tax periods remain open to examination by the Internal Revenue Service and the 2011 through 2015 tax periods remain open to examination by most state tax authorities.

Related-Party Transactions	12 Months Ended
Related-Party Transactions	Dec. 31, 2015
Related-Party Transactions
Related Party Transactions	Related-Party Transactions During the year ended December 31, 2015, four members of the Company’s Board of Directors also served on the boards of directors of RPX clients. During the year ended December 31, 2014, five members of the Company’s Board of Directors also served on the boards of directors of RPX clients. During the year ended December 31, 2013, four members of the Company’s Board of Directors also served on the board of directors of an RPX client. The Company recognized subscription revenue from these clients in the amount of $9.3 million, $9.4 million and $5.1 million during the years ended December 31, 2015, 2014 and 2013, respectively. The Company recognized selling, general, and administrative expenses from products and services provided by these clients of $0.3 million, $0.2 million, and $0.2 million for each year ended December 31, 2015, 2014 and 2013, respectively. There were nil and $0.1 million of receivables due from these clients as of December 31, 2015 and 2014, respectively.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References + Details

Employee Savings Plan	12 Months Ended
Employee Savings Plan	Dec. 31, 2015
Employee Savings Plan [Abstract]
Employee Savings Plan	. Employee Savings Plan The Company has a savings plan, which qualifies under Section 401(k) of the Internal Revenue Code (the “Plan”), available for its employees in the United States who meet the Plan’s age and service requirements. Employees are eligible to participate in the Plan in the month following their 3-month anniversary with the Company. Under the terms of the Plan, employees may make voluntary contributions up to maximum statutory limits. The Company elected to contribute a discretionary match of one dollar for each dollar contributed, with a maximum employer contribution for each United States employee of $5,000 for each of the years ended December 31, 2015 and 2014, respectively. The Company recorded contribution expense of $0.5 million and $0.4 million during the years ended December 31, 2015 and 2014, respectively.

Segment Reporting

12 Months Ended

Dec. 31, 2015

Segment Reporting

Segment Reporting

Operating segments are components of an enterprise about which separate financial information is available. Operating segments are reported in a manner consistent with the internal reporting provided to the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker is its Chief Executive Officer. The Company’s Chief Executive Office reviews financial information presented on a consolidated basis and, as a result, the Company concluded that there is only one operating and reportable segment.

The Company markets its solution to companies around the world. Revenue is generally attributed to geographic areas based on the country in which the client is domiciled.

The following table presents revenue by location and revenue generated by country as a percentage of total revenue for the applicable period, for countries representing 10% or more of revenues for one or more of the periods presented (dollars in thousands):



	Year Ended December 31,
	2015				2014				2013
United States	$	186,439	64	%	$	166,593	64	%	$	145,310	61	%
Japan	36,195		12		36,849		14		39,465		17
Korea	28,319		10		17,847		7		12,552		5
Other	40,928		14		38,046		15		40,177		17
Total revenue	$	291,881	100	%	$	259,335	100	%	$	237,504	100	%

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=51669610&loc=d3e8981-108599

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 41
-URI http://asc.fasb.org/extlink&oid=51669610&loc=d3e9038-108599

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 9: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Reference 10: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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-URI http://asc.fasb.org/extlink&oid=51669610&loc=d3e8906-108599

+ Details

Subsequent Events (Notes)	12 Months Ended
Subsequent Events (Notes)	Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On January 22, 2016, the Company and National Acquisition Corp., a Delaware corporation and a wholly-owned subsidiary of the Company, completed a transaction to acquire 100% of outstanding shares of Inventus Solutions, Inc. (“Inventus”), a Delaware corporation, for an aggregate purchase price of $232 million, less certain transaction expenses and subject to customary working capital adjustments. The acquisition expands the Company's business into the litigation discovery management market. The Company is currently in the process of valuing the assets acquired and liabilities assumed in the transaction and the initial accounting for the acquisition, including the preliminary allocation of purchase price, is incomplete as of the date of filing this Annual Report on Form 10-K.

Selected Quarterly Financial Information (Unaudited)

12 Months Ended

Dec. 31, 2015

Quarterly Financial Information Disclosure (Unaudited) [Abstract]

Selected Quarterly Financial Information (Unaudited)

Summarized quarterly financial information for the years ended December 31, 2015 and 2014 is as follows (in thousands, except per share data):



	Three Months Ended
	March 31, 2015		June 30, 2015			September 30, 2015		December 31, 2015
Revenue	$	83,287	$	67,551		$	68,212	$	72,831
Cost of revenue	34,759		36,985			37,639		39,475
Selling, general and administrative expenses	19,459		18,997			18,773		20,199
Gain on sale of patent assets	—		(592		)	—		—
Operating income	29,069		12,161			11,800		13,157
Other income (expense), net ⁽¹⁾	121		934			876		(2,619		)
Income before provision for income taxes	29,190		13,095			12,676		10,538
Provision for income taxes	11,159		5,065			4,842		5,011
Net income	$	18,031	$	8,030		$	7,834	$	5,527

Net income per share⁽²⁾:
Basic	$	0.33	$	0.15		$	0.14	$	0.10
Diluted	$	0.33	$	0.14		$	0.14	$	0.10

Other Data:
Deferred revenue, including current portion	$	158,411	$	142,623		$	117,431	$	115,652
Stock-based compensation expense	$	3,881	$	4,644		$	4,603	$	4,466



	Three Months Ended
	March 31, 2014		June 30, 2014			September 30, 2014			December 31, 2014
Revenue	$	61,888	$	64,293		$	65,407		$	67,747
Cost of revenue	28,920		31,542			30,444			33,529
Selling, general and administrative expenses	17,255		18,579			17,786			18,059
Gain on sale of patent assets	—		(699		)	(8		)	—
Operating income	15,713		14,871			17,185			16,159
Other income, net	99		94			73			88
Income before provision for income taxes	15,812		14,965			17,258			16,247
Provision for income taxes	5,952		5,566			6,425			6,998
Net income	$	9,860	$	9,399		$	10,833		$	9,249

Net income per share⁽²⁾:
Basic	$	0.19	$	0.18		$	0.20		$	0.17
Diluted	$	0.18	$	0.17		$	0.20		$	0.17

Other Data:
Deferred revenue, including current portion	$	140,534	$	131,207		$	112,820		$	136,209
Stock-based compensation expense	$	3,803	$	5,065		$	4,486		$	4,302

⁽¹⁾See Note 10, "Commitments and Contingencies" for further information regarding other income (expense), net.

⁽²⁾Basic and diluted earnings per share are computed independently for each of the quarters presented. Therefore, the sum of quarterly basic and diluted per share information may not equal annual basic and diluted earnings per share.

Basis of Presentation and Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2015

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Basis of Presentation

Use of Estimates

Significant estimates and assumptions made by management include the determination of:


•	the estimated economic useful lives of patent assets;


•	the determination of a best estimated selling price of a subscription to the Company’s patent risk management solution and its insurance offering;


•	the fair value of assets acquired and liabilities assumed for business combinations;


•	recognition and measurement of current and deferred income taxes, any related valuation allowances, and uncertain tax positions;


•	the fair value of stock awards issued;


•	the assumptions and methods used in deriving the fair value of deferred payment obligations; and


•	the estimated reserves for known and incurred but not reported claims.

Revenue Recognition


•	Persuasive evidence of an arrangement exists. All subscription fees are supported by an executed subscription agreement.

•


•	Collectability is reasonably assured. Subscription fees are generally collected on or near the effective date of the agreement and again at or near each anniversary date thereof. The Company does not recognize revenue in instances where collectability is not reasonably assured. Generally, the Company’s subscription agreements state that all fees paid are non-refundable.

Key indicators evaluated to determine the Company's role as either principal or agent in the transaction include, among others:


•	the seller of the patent assets is generally viewed as the primary obligor in the arrangement, given that it owns and controls the underlying patent(s) and thus has the absolute authority to grant and deliver any release from past damages and dismissal from litigation, as well the general terms of the license granted;


•	the Company has no inventory risk, as the clients generally enter into their contractual obligations with the Company prior to or contemporaneous to the Company entering into a contractual obligation with the seller;


•	the Company generally has limited pricing latitude as client contributions are based on the sales price set by the seller;


•	the Company is not involved in the determination of the product or service specification and has no ability to change the product or perform any part of the service in connection with these transactions, as the seller owns the underlying patent(s); and


•	the Company has limited or no credit risk, as each respective client has a contractually binding obligation, such clients are generally of high credit quality and in many instances, the Company collects the client contribution prior to making a payment to the seller.

In certain syndicated transactions, the Company may recognize revenue upon the sale of licenses to specific patent assets and/or upon completion of the rendering of advisory services.

The Company has determined its best estimate of selling price (“BESP”) for a subscription to our patent risk management solution based on the following:

•

The Company has determined its BESP for its insurance product based on the following:

•

Accounting fo Payments to Clients

Accounting for Payments to Clients

Deferred Revenue

Accounts Receivable

Concentration of Risk

Fair Value Measurements

Level 1 – Valuations based on quoted prices in active markets for identical assets or liabilities and readily accessible by the Company at the reporting date.

Level 3 – Valuations based on inputs that are unobservable.

Cash and Cash Equivalents

Short-Term Investments

Property and Equipment

Property and Equipment, Net

Internal-Use Software and Website Development Costs

Patent Assets, Net

In instances where the Company sells patent assets, the amount of consideration received is compared to the asset’s carrying value to determine and recognize a gain or loss.

Impairment of Long-Lived Assets

Goodwill

Intangible Assets, Net

Advertising Costs

The Company expenses advertising costs as they are incurred. Advertising expenses were not material for any of the periods presented

Foreign Currency Accounting

Income Taxes

Stock-Based Compensation

Business Combinations

Reserves for Known and Incurred but not Reported Claims

Recently Adopted Accounting Standards

Recent Accounting Pronouncements

Net Income Available to Common Stockholders (Tables)

12 Months Ended

Dec. 31, 2015

Net Income Available to Common Stockholders

Basic and Diluted Net Income Per Share Available To Common Stockholders

The following table presents the calculation of basic and diluted net income per share available to common stockholders (in thousands, except for per share data):



	Year Ended December 31,
	2015		2014		2013
Net income available to common stockholders:
Numerator:
Net income	$	39,422	$	39,341	$	40,783
Allocation of net income to participating stockholders	—		—		(20		)
Net income available to common stockholders	$	39,422	$	39,341	$	40,763
Denominator:
Basic shares:
Weighted-average shares used in computing basic net income available to common stockholders	54,432		53,444		51,956
Diluted shares:
Weighted-average shares used in computing basic net income available to common stockholders	54,432		53,444		51,956
Dilutive effect of stock options and restricted stock units using treasury-stock method	978		1,374		1,696
Weighted-average shares used in computing diluted net income available to common stockholders	55,410		54,818		53,652
Net income per common share available to common stockholders:
Basic	$	0.72	$	0.74	$	0.78
Diluted	$	0.71	$	0.72	$	0.76

Anti-Dilutive Securities Not Included In Diluted Shares Outstanding Calculation



	Year Ended December 31,
	2015	2014	2013
Weighted-average:
Stock options outstanding	663	767	1,215
Restricted stock units outstanding	263	100	127
Shares of common stock subject to repurchase	—	—	25

Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

Schedule of financial assets and liabilities measured at fair value on a recurring basis



	December 31, 2015
	Amortized Cost		Unrealized					Estimated Fair Value		Level 1		Level 2		Level 3
	Amortized Cost		Gains		Losses			Estimated Fair Value		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
Commercial paper	$	7,997	$	—	$	—		$	7,997	$	—	$	7,997	$	—
Municipal bonds	1,635		—		—			1,635		—		1,635		—
Money market funds	54,663		—		—			54,663		54,663		—		—
	$	64,295	$	—	$	—		$	64,295	$	54,663	$	9,632	$	—
Short-term investments:
Municipal bonds	$	133,033	$	—	$	(96	)	132,937		$	—	$	132,937	$	—
Commercial paper	5,493		—		(3		)	5,490		—		5,490		—
Corporate bonds	30,488		3		(93		)	30,398		—		30,398		—
U.S. government and agency securities	61,559		—		(62		)	61,497		—		61,497		—
Equity securities	123		—		—			123		123		—		—
	$	230,696	$	3	$	(254	)	$	230,445	$	123	$	230,322	$	—
Liabilities:
Current liabilities:
Deferred payment obligations	$	6,270	$	3,887	$	—		$	2,383	$	—	$	—	$	2,383



	December 31, 2014
	Amortized Cost		Unrealized					Estimated Fair Value		Level 1		Level 2		Level 3
	Amortized Cost		Gains		Losses			Estimated Fair Value		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
Commercial paper	$	5,749	$	—	$	—		$	5,749	$	—	$	5,749	$	—
U.S. government and agency securities	2,000		—		—			2,000		—		2,000		—
Municipal bonds	1,409		—		—			1,409		—		1,409		—
Money market funds	451		—		—			451		451		—		—
	$	9,609	$	—	$	—		$	9,609	$	451	$	9,158	$	—
Short-term investments:
Municipal bonds	$	120,270	$	24	$	(12	)	$	120,282	$	—	$	120,282	$	—
Commercial paper	2,498		—		—			2,498		—		2,498		—
Corporate bonds	68,758		1		(87		)	68,672		—		68,672		—
U.S. government and agency securities	48,095		—		(33		)	48,062		—		48,062		—
	$	239,621	$	25	$	(132	)	$	239,514	$	—	$	239,514	$	—

Patent Assets, Net (Tables)

12 Months Ended

Dec. 31, 2015

Patent Assets [Abstract]

Patent Assets, Net

Patent assets, net consisted of the following (in thousands):



	December 31, 2014			Additions			Sales			December 31, 2015
Patent assets	$	665,290		$	160,664		$	(1,696	)	$	824,258
Accumulated amortization	(428,941		)	(142,296		)	1,539			(569,698		)
Patent assets, net	$	236,349								$	254,560



	December 31, 2013			Additions			Sales			December 31, 2014
Patent assets	$	529,526		$	136,468		$	(704	)	$	665,290
Accumulated amortization	(309,572		)	(119,694		)	325			(428,941		)
Patent assets, net	$	219,954								$	236,349

Expected Future Annual Amortization Of Patent Assets

s of December 31, 2015, the Company expects amortization expense in future periods to be as follows (in thousands):



2016	$	136,322
2017	74,725
2018	25,841
2019	14,662
2020	3,010
Total estimated future amortization expense	$	254,560

Property and Equipment, Net (Tables)	12 Months Ended
Property and Equipment, Net (Tables)	Dec. 31, 2015
Property and Equipment, Net
Property And Equipment, Net	t Property and equipment, net, consisted of the following (in thousands):

Intangible Assets, Net (Tables)

12 Months Ended

Dec. 31, 2015

Acquired Finite-Lived Intangible Assets [Line Items]

Intangible Assets, Net

Intangible assets, net, as of December 31, 2015 and 2014 consisted of the following (in thousands except years):



		December 31, 2015							December 31, 2014
	Weighted-Average Life Remaining (years)	Carrying Amount		Accumulated Amortization			Net Carrying Amount		Carrying Amount		Accumulated Amortization			Net Carrying Amount
Proprietary data and models	3.8	$	2,100	$	(1,694	)	$	406	$	2,100	$	(1,119	)	$	981
Trademarks	3.6	1,720		(1,645		)	75		1,890		(1,565		)	325
Developed technology	2.6	120		(120		)	—		433		(433		)	—
Customer relationships	3.0	1,050		(659		)	391		1,050		(392		)	658
Covenant not to compete	3.0	1,900		(971		)	929		1,920		(358		)	1,562
		$	6,890	$	(5,089	)	$	1,801	$	7,393	$	(3,867	)	$	3,526

Expected Future Annual Amortization Of Intangible Assets

s of December 31, 2015, the Company expects amortization expense in future periods to be as follows (in thousands):



2016	$	136,322
2017	74,725
2018	25,841
2019	14,662
2020	3,010
Total estimated future amortization expense	$	254,560

Intangible Assets Net

Acquired Finite-Lived Intangible Assets [Line Items]

Expected Future Annual Amortization Of Intangible Assets

(in thousands):



2016	$	1,288
2017	513
Total estimated future amortization expense	$	1,801

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2015

Commitments and Contingencies Disclosure [Abstract]

Aggregate Future Non-Cancelable Minimum Lease Payments For Operating Leases

As of December 31, 2015, the future minimum lease payments required under non-cancelable operating leases and the future minimum payments to be received from non-cancelable subleases were as follows:



2016	$	4,284
2017	4,206
2018	4,273
2019	3,613
Future non-cancelable minimum operating lease payments	16,376
Less: minimum payments to be received from non-cancelable subleases	(787		)
Total future non-cancelable minimum operating lease payments, net	$	15,589

Stockholder's Equity (Tables)

12 Months Ended

Dec. 31, 2015

Stock-Based Compensation

Activity Under Equity Settled Award Plans And Related Information

A summary of the Company’s activity under its equity-settled award plans and related information is as follows (in thousands, except per share data):



			Options Outstanding
	Shares Available for Grant		Number of Shares		Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Life in Years	Aggregate Intrinsic Value
Balance - December 31, 2014	2,685		3,264		$	10.38
Shares authorized	1,000		—		—
Options exercised	—		(778	)	6.44
Options forfeited	146		(146	)	19.63
Restricted stock units granted	(1,433	)	—		—
Restricted stock units forfeited	407		—		—
Restricted stock units withheld related to net share settlement of restricted stock units	354		—		—
Balance - December 31, 2015	3,159		2,340		11.11		5.2	$	4,430
Vested and exercisable - December 31, 2015			2,093		11.44		5.2	3,739
Vested and expected to vest - December 31, 2015			2,327		11.13		5.2	4,390

Restricted Stock Unit Activity

The summary of restricted stock unit activity, which includes PBRSUs, is as follows (in thousands, except for per share data):



	Number of Shares		Weighted-Average Grant Date Fair Value		Aggregate Intrinsic Value
Non-vested units - December 31, 2014	2,460		$	13.15
Granted	1,433		14.09
Vested	(996	)	14.00
Forfeited	(407	)	13.29
Non-vested units - December 31, 2015	2,490		13.35		$	28,109

Weighted-Average Assumptions Used To Estimate The Fair Value Of Stock Options



	Year Ended December 31,
	2013
Dividend yield	—		%
Risk-free rate	0.93		%
Expected volatility	61		%
Expected term (in years)	6.1
Grant date fair value	$	7.39

Weighted-Average Assumptions Used To Estimate The Fair Value Of PBRSUs



	Year Ended December 31,
	2014			2013
Dividend yield	—			—
Risk free rate	1.11		%	0.59		%
Expected volatility	48		%	53		%
Grant date fair value	$	7.47		$	6.39

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Income Before Income Tax Provision

Income before income tax provision consists of the following (in thousands):



	Year Ended December 31,
	2015		2014		2013
Domestic	$	65,445	$	64,238	$	64,281
International	54		44		14
Total income before provision for income taxes	$	65,499	$	64,282	$	64,295

Components Of The Provision For Income Taxes

The components of the provision for income taxes are as follows (in thousands):



	Year Ended December 31,
	2015			2014			2013
Current:
Federal	$	(23,456	)	$	(26,517	)	$	(17,145	)
State	(2,790		)	(3,031		)	(1,188		)
Foreign	(12,406		)	(9,611		)	(8,220		)
Total current provision for income taxes	(38,652		)	(39,159		)	(26,553		)
Deferred:
Federal	12,022			13,668			2,920
State	553			550			121
Total deferred benefit for income taxes	12,575			14,218			3,041
Total provision for income taxes	$	(26,077	)	$	(24,941	)	$	(23,512	)

Net Deferred Tax Liabilities

Net deferred tax assets (liabilities) consist of the following (in thousands):



	December 31,
	2015			2014
Deferred tax assets:
Deferred revenue	$	1,438		$	2,779
Reserves and other	5,017			2,319
Stock-based compensation	5,701			5,963
Depreciation and amortization	5,560			—
Total deferred tax assets	17,716			11,061
Valuation allowance	(1,097		)	—
Net deferred tax assets	16,619			11,061

Deferred tax liabilities:
Depreciation and amortization	—			(6,568		)
Net deferred tax liabilities	—			(6,568		)

Net deferred taxes	$	16,619		$	4,493

Reconciliation Of The Statutory Federal Income Tax To Effective Tax

The following is a reconciliation of the statutory federal income tax to the Company’s effective tax (in thousands):



	Year Ended December 31,
	2015			2014			2013
Tax at statutory federal rate	$	(22,939	)	$	(22,498	)	$	(22,503	)
State tax – net of federal benefit	(1,459		)	(1,678		)	(655		)
Permanent differences	(663		)	(879		)	(569		)
Foreign tax	(12,370		)	(9,576		)	(8,214		)
Foreign tax credits	12,370			9,576			8,216
Foreign income not taxed at federal rate	(3		)	(3		)	1
Change in valuation allowance	(1,097		)	—			—
Other	84			117			212
Total provision for income taxes	$	(26,077	)	$	(24,941	)	$	(23,512	)

Unrecognized Tax Benefits

The following table summarizes the activity related to the Company’s unrecognized tax benefits (in thousands):



	2015		2014			2013
Balance as of January 1,	$	3,707	$	2,036		$	1,136
Gross increase related to current period tax positions	1,606		1,672			1,043
Gross increase (decrease) related to prior period tax positions	2		(1		)	(143		)
Balance as of December 31,	$	5,315	$	3,707		$	2,036

Segment Reporting (Tables)

12 Months Ended

Dec. 31, 2015

Segment Reporting

Revenue By Location



	Year Ended December 31,
	2015				2014				2013
United States	$	186,439	64	%	$	166,593	64	%	$	145,310	61	%
Japan	36,195		12		36,849		14		39,465		17
Korea	28,319		10		17,847		7		12,552		5
Other	40,928		14		38,046		15		40,177		17
Total revenue	$	291,881	100	%	$	259,335	100	%	$	237,504	100	%

Selected Quarterly Financial Information (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2015

Quarterly Financial Information Disclosure (Unaudited) [Abstract]

Selected Quarterly Financial Information (Unaudited)

Summarized quarterly financial information for the years ended December 31, 2015 and 2014 is as follows (in thousands, except per share data):



	Three Months Ended
	March 31, 2015		June 30, 2015			September 30, 2015		December 31, 2015
Revenue	$	83,287	$	67,551		$	68,212	$	72,831
Cost of revenue	34,759		36,985			37,639		39,475
Selling, general and administrative expenses	19,459		18,997			18,773		20,199
Gain on sale of patent assets	—		(592		)	—		—
Operating income	29,069		12,161			11,800		13,157
Other income (expense), net ⁽¹⁾	121		934			876		(2,619		)
Income before provision for income taxes	29,190		13,095			12,676		10,538
Provision for income taxes	11,159		5,065			4,842		5,011
Net income	$	18,031	$	8,030		$	7,834	$	5,527

Net income per share⁽²⁾:
Basic	$	0.33	$	0.15		$	0.14	$	0.10
Diluted	$	0.33	$	0.14		$	0.14	$	0.10

Other Data:
Deferred revenue, including current portion	$	158,411	$	142,623		$	117,431	$	115,652
Stock-based compensation expense	$	3,881	$	4,644		$	4,603	$	4,466



	Three Months Ended
	March 31, 2014		June 30, 2014			September 30, 2014			December 31, 2014
Revenue	$	61,888	$	64,293		$	65,407		$	67,747
Cost of revenue	28,920		31,542			30,444			33,529
Selling, general and administrative expenses	17,255		18,579			17,786			18,059
Gain on sale of patent assets	—		(699		)	(8		)	—
Operating income	15,713		14,871			17,185			16,159
Other income, net	99		94			73			88
Income before provision for income taxes	15,812		14,965			17,258			16,247
Provision for income taxes	5,952		5,566			6,425			6,998
Net income	$	9,860	$	9,399		$	10,833		$	9,249

Net income per share⁽²⁾:
Basic	$	0.19	$	0.18		$	0.20		$	0.17
Diluted	$	0.18	$	0.17		$	0.20		$	0.17

Other Data:
Deferred revenue, including current portion	$	140,534	$	131,207		$	112,820		$	136,209
Stock-based compensation expense	$	3,803	$	5,065		$	4,486		$	4,302

⁽¹⁾See Note 10, "Commitments and Contingencies" for further information regarding other income (expense), net.

Basis of Presentation and Significant Accounting Policies (Details) $ in Thousands	3 Months Ended	12 Months Ended			78 Months Ended
	Mar. 31, 2014	Dec. 31, 2015 USD ($) significant_client	Dec. 31, 2014 USD ($) significant_client	Dec. 31, 2013 USD ($) significant_client	Dec. 31, 2014 USD ($) significant_client
Basis of Presentation and Significant Accounting Polcies [Line Items]
Deferred Tax Assets, Gross, Current		$ (16,619)	$ (4,493)		$ (4,493)
Other than Temporary Impairment Losses, Investments		$ (5,100)	0
BESP 5pct of Revenue		0.00%
Restricted cash (current and non-current)		$ 1,428	1,675		$ 1,675
Capitalization of internal-use sofware and website development costs		2,300	1,200	$ 1,200
Amortization of internal-use sofware and website development costs		$ 1,100	$ 1,300	$ 1,100
Accounts receivable
Basis of Presentation and Significant Accounting Polcies [Line Items]
Number of Significant Clients \| significant_client		3	3		3
Sales Revenue, Subscription Fee
Basis of Presentation and Significant Accounting Polcies [Line Items]
Number of Significant Clients \| significant_client		0	0	0	0
Client One \| Accounts receivable
Basis of Presentation and Significant Accounting Polcies [Line Items]
Concentration of credit risk, percentage		32.00%	28.00%
Client Two \| Accounts receivable
Basis of Presentation and Significant Accounting Polcies [Line Items]
Concentration of credit risk, percentage		18.00%	24.00%
Client Three \| Accounts receivable
Basis of Presentation and Significant Accounting Polcies [Line Items]
Concentration of credit risk, percentage		14.00%	14.00%
Internal-use software
Basis of Presentation and Significant Accounting Polcies [Line Items]
Patent assets, useful life		3 years
Weighted Average \| Patents
Basis of Presentation and Significant Accounting Polcies [Line Items]
Patent assets, useful life		38 months			44 months
Maximum
Basis of Presentation and Significant Accounting Polcies [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Maximum \| Patents
Basis of Presentation and Significant Accounting Polcies [Line Items]
Patent assets, useful life		60 months
Minimum
Basis of Presentation and Significant Accounting Polcies [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Minimum \| Patents
Basis of Presentation and Significant Accounting Polcies [Line Items]
Patent assets, useful life		24 months
New Accounting Pronouncement, Early Adoption, Effect [Member]
Basis of Presentation and Significant Accounting Polcies [Line Items]
Deferred Tax Assets, Gross, Current			$ 4,400		$ 4,400

Net Income Available to Common Stockholders (Detail) - Basic and Diluted Net Income Per Share Available To Common Stockholders - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Basic:
Net income	$ 5,527	$ 7,834	$ 8,030	$ 18,031	$ 9,249	$ 10,833	$ 9,399	$ 9,860	$ 39,422	$ 39,341	$ 40,783
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic									0	0	20
Net income available to common stockholders – basic									39,422	39,341	40,763
Diluted:
Net income available to common stockholders – diluted									$ 39,422	$ 39,341	$ 40,763
Basic shares:
Weighted-average shares used in computing basic net income available to comon stockholders									54,432	53,444	51,956
Diluted shares:
Dilutive effect of stock options and restricted stock units using treasury-stock method									978	1,374	1,696
Weighted-average shares used in computing diluted net income available to common stockholders									55,410	54,818	53,652
Net income per common share available to common stockholders:
Basic	$ 0.10	$ 0.14	$ 0.15	$ 0.33	$ 0.17	$ 0.20	$ 0.18	$ 0.19	$ 0.72	$ 0.74	$ 0.78
Diluted	$ 0.10	$ 0.14	$ 0.14	$ 0.33	$ 0.17	$ 0.20	$ 0.17	$ 0.18	$ 0.71	$ 0.72	$ 0.76

Net Income Available to Common Stockholders (Detail) - Anti-Dilutive Securities Not Included In Diluted Shares Outstanding Calculation - shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock options outstanding
Weighted-average:
Weighted-average anti-dilutive securities	663	767	1,215
Restricted stock units outstanding
Weighted-average:
Weighted-average anti-dilutive securities	263	100	127
Shares of common stock subject to repurchase
Weighted-average:
Weighted-average anti-dilutive securities	0	0	25

Financial Instruments - Schedule of Financial Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Current Fiscal Year End Date	--12-31
Assets:
Cash equivalents:	$ 64,295		$ 9,609
Short-term investments:
Short-term investments amortized cost	230,696		239,621
Short-term investments unrealized gains	3		25
Short-term investments unrealized losses	254		132
Estimated fair value	230,445		239,514
Level 1
Assets:
Cash equivalents:	54,663		451
Short-term investments:
Short-term investments fair value levels	123		0
Level 2
Assets:
Cash equivalents:	9,632		9,158
Short-term investments:
Short-term investments fair value levels	230,322		239,514
Level 3
Assets:
Cash equivalents:	0		0
Short-term investments:
Short-term investments fair value levels	0		0
Deferred payment obligations
Current liabilities:
Deferred payment obligations amortized costs	6,270	$ 6,300
Deferred payment obligations unrealized gains	3,887
Deferred payment obligations fair value	2,383
Deferred payment obligations \| Level 1
Current liabilities:
Deferred payment obligations fair value	0
Deferred payment obligations \| Level 2
Current liabilities:
Deferred payment obligations fair value	0
Deferred payment obligations \| Level 3
Current liabilities:
Deferred payment obligations fair value	2,383
Corporate bonds
Short-term investments:
Short-term investments amortized cost	30,488		68,758
Short-term investments unrealized gains	3		1
Short-term investments unrealized losses	93		87
Estimated fair value	30,398		68,672
Corporate bonds \| Level 1
Short-term investments:
Short-term investments fair value levels	0		0
Corporate bonds \| Level 2
Short-term investments:
Short-term investments fair value levels	30,398		68,672
Corporate bonds \| Level 3
Short-term investments:
Short-term investments fair value levels	0		0
Commercial paper
Short-term investments:
Short-term investments amortized cost	5,493		2,498
Short-term investments unrealized gains	0		0
Short-term investments unrealized losses	3		0
Estimated fair value	5,490		2,498
Commercial paper \| Level 1
Short-term investments:
Short-term investments fair value levels	0		0
Commercial paper \| Level 2
Short-term investments:
Short-term investments fair value levels	5,490		2,498
Commercial paper \| Level 3
Short-term investments:
Short-term investments fair value levels	0		0
Municipal bonds
Short-term investments:
Short-term investments amortized cost	133,033		120,270
Short-term investments unrealized gains	0		24
Short-term investments unrealized losses	96		12
Estimated fair value	132,937		120,282
Municipal bonds \| Level 1
Short-term investments:
Short-term investments fair value levels	0		0
Municipal bonds \| Level 2
Short-term investments:
Short-term investments fair value levels	132,937		120,282
Municipal bonds \| Level 3
Short-term investments:
Short-term investments fair value levels	0		0
U.S. government and agency securities
Short-term investments:
Short-term investments amortized cost	61,559		48,095
Short-term investments unrealized gains	0		0
Short-term investments unrealized losses	62		33
Estimated fair value	61,497		48,062
U.S. government and agency securities \| Level 1
Short-term investments:
Short-term investments fair value levels	0		0
U.S. government and agency securities \| Level 2
Short-term investments:
Short-term investments fair value levels	61,497		48,062
U.S. government and agency securities \| Level 3
Short-term investments:
Short-term investments fair value levels	0		0
Equity securities
Short-term investments:
Short-term investments amortized cost	123
Short-term investments unrealized gains	0
Short-term investments unrealized losses	0
Estimated fair value	123
Equity securities \| Level 1
Short-term investments:
Short-term investments fair value levels	123
Equity securities \| Level 2
Short-term investments:
Short-term investments fair value levels	0
Equity securities \| Level 3
Short-term investments:
Short-term investments fair value levels	0
U.S. government and agency securities
Assets:
Cash equivalents:			2,000
U.S. government and agency securities \| Level 1
Assets:
Cash equivalents:			0
U.S. government and agency securities \| Level 2
Assets:
Cash equivalents:			2,000
U.S. government and agency securities \| Level 3
Assets:
Cash equivalents:			0
Commercial paper
Assets:
Cash equivalents:	7,997		5,749
Commercial paper \| Level 1
Assets:
Cash equivalents:	0		0
Commercial paper \| Level 2
Assets:
Cash equivalents:	7,997		5,749
Commercial paper \| Level 3
Assets:
Cash equivalents:	0		0
Municipal bonds
Assets:
Cash equivalents:	1,635		1,409
Municipal bonds \| Level 1
Assets:
Cash equivalents:	0		0
Municipal bonds \| Level 2
Assets:
Cash equivalents:	1,635		1,409
Municipal bonds \| Level 3
Assets:
Cash equivalents:	0		0
Money market funds
Assets:
Cash equivalents:	54,663		451
Money market funds \| Level 1
Assets:
Cash equivalents:	54,663		451
Money market funds \| Level 2
Assets:
Cash equivalents:	0		0
Money market funds \| Level 3
Assets:
Cash equivalents:	$ 0		$ 0

Financial Instruments - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Current Fiscal Year End Date		--12-31
Losses in other income (expense)		$ 3,444	$ 0	$ 0
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net		$ 5,096	$ 0	$ 0
Percentage of marketable security investments that mature in one year		87.00%	76.00%
Percentage of marketable security investments that mature within one to five years		13.00%	24.00%
Short-term cost method investments		$ 600	$ 0
Funding from a syndicate participant	$ 6,300	6,300
Other Debt Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of loan from syndicate participant		2,383
Level 3 \| Other Debt Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of loan from syndicate participant		$ 2,383
Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Maturity period		1 year
Maturity period, year two through five		1 year
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Maturity period, year two through five		5 years

Patent Assets, Net (Detail) $ in Thousands			12 Months Ended			78 Months Ended
Patent Assets, Net (Detail) $ in Thousands	Jan. 28, 2015 USD ($) syndicate_company	Dec. 26, 2014 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Document Period End Date			Dec. 31, 2015
Amortization of patent assets			$ 1,700	$ 1,500	$ 1,500
Patents
Finite-Lived Intangible Assets [Line Items]
Amortization of patent assets			$ 142,400	$ 119,700	$ 105,500
Minimum \| Patents
Finite-Lived Intangible Assets [Line Items]
Patent assets, useful life			24 months
Maximum \| Patents
Finite-Lived Intangible Assets [Line Items]
Patent assets, useful life			60 months
Weighted Average \| Patents
Finite-Lived Intangible Assets [Line Items]
Patent assets, useful life			38 months			44 months
Subsidiaries [Member]
Finite-Lived Intangible Assets [Line Items]
Escrow Deposits Related to Patent Assets	$ 875,000	$ 25,000
Number of Companies Involved in Syndicate \| syndicate_company	30
Finite-lived Intangible Assets Acquired	$ 29,000
Subsidiaries [Member] \| Patents
Finite-Lived Intangible Assets [Line Items]
Patent assets, useful life	60 months

Patent Assets, Net (Detail) - Patent Assets, Net - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Patent assets	$ (6,890)	$ (7,393)
Accumulated amortization	(5,089)	(3,867)
Patent assets, net	254,560	236,349
Patents
Finite-Lived Intangible Assets [Line Items]
Patent assets	(824,258)	(665,290)	$ (529,526)
Accumulated amortization	(569,698)	(428,941)	(309,572)
Patent assets, net	254,560	236,349	$ 219,954
Additions \| Patents
Finite-Lived Intangible Assets [Line Items]
Patent assets	(160,664)	(136,468)
Accumulated amortization	(142,296)	(119,694)
Dispositions \| Patents
Finite-Lived Intangible Assets [Line Items]
Patent assets	(1,696)	(704)
Accumulated amortization	$ (1,539)	$ (325)

Patent Assets, Net (Detail) - Expected Future Annual Amortization Expense Of Patent Assets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
2015	$ 1,288
2016	513
Total estimated future amortization expense	254,560	$ 236,349
Patents
Finite-Lived Intangible Assets [Line Items]
2015	136,322
2016	74,725
2017	25,841
2018	14,662
2019	3,010
Total estimated future amortization expense	$ 254,560	$ 236,349	$ 219,954

Property and Equipment, Net (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense	$ 145,835	$ 123,138	$ 108,629
Internal-use software
Property, Plant and Equipment [Line Items]
Stock-based compensation capitalized as part of internal-use software	100	100	100
Property and equipment, types
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense	$ 1,700	$ 2,000	$ 1,600

Property and Equipment, Net (Detail) - Property And Equipment, Net - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 11,658	$ 9,363
Less: Accumulated depreciation and amortization	(6,925)	(5,212)
Total property and equipment, net	4,733	4,151
Internal-use software
Property, Plant and Equipment [Line Items]
Internal-use software	7,654	5,358
Leasehold improvements
Property, Plant and Equipment [Line Items]
Leasehold improvements	1,799	1,799
Computer, equipment and software
Property, Plant and Equipment [Line Items]
Computer, equipment and software	1,387	1,221
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Furniture and fixtures	818	818
Construction-in-progress
Property, Plant and Equipment [Line Items]
Construction-in-progress	$ 0	$ 167

Goodwill (Detail) - Changes In The Carrying Amounts Of Goodwill - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Acquired Finite-Lived Intangible Assets [Line Items]
Balance as of January 1,	$ 19,978	$ 16,460
Goodwill from business acquisition	0	3,518
Balance as of December 31,	$ 19,978	$ 19,978

Intangible Assets, Net (Detail) - USD ($) $ in Thousands	12 Months Ended
Intangible Assets, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Intangible Assets, Net
Amortization of intangible assets	$ 1,700	$ 1,500	$ 1,500

Intangible Assets, Net (Detail) - Intangible Assets, Net - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	$ 6,890	$ 7,393
Accumulated amortization	(5,089)	(3,867)
Net carrying amount	1,801	3,526
Proprietary data and models
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	2,100	2,100
Accumulated amortization	(1,694)	(1,119)
Net carrying amount	406	981
Trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	1,720	1,890
Accumulated amortization	(1,645)	(1,565)
Net carrying amount	75	325
Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	120	433
Accumulated amortization	(120)	(433)
Net carrying amount	0	0
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	1,050	1,050
Accumulated amortization	(659)	(392)
Net carrying amount	391	658
Covenant not to compete
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	1,900	1,920
Accumulated amortization	(971)	(358)
Net carrying amount	$ 929	$ 1,562

Intangible Assets, Net (Detail) - Estimated Future Amortization Expenses For Intangible Assets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Estimated Future Amortization Expenses for Intangible Assets [Abstract]
2015	$ 1,288
2016	513
Total estimated future amortization expense	$ 1,801	$ 3,526

Accrued and Other Current Liabilities (Detail) - Accrued And Other Current Liabilities - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Accrued liabilities	$ 14,842	$ 14,257
Other current liabilities	467	640
Accrued payroll-related expenses
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Accrued liabilities	11,105	9,270
Accrued expenses
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Accrued liabilities	$ 3,737	$ 4,987

Commitments and Contingencies (Detail) $ in Thousands		9 Months Ended	12 Months Ended
Commitments and Contingencies (Detail) $ in Thousands	Mar. 31, 2012 ft² defendant	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) insurance_policy	Dec. 31, 2014 USD ($) insurance_policy	Dec. 31, 2013 USD ($)	Jan. 28, 2015 USD ($)
Loss Contingencies [Line Items]
Area of real estate property (in square feet) \| ft²	67,000
Monthly base rent payments			$ 300
Operating Leases, Income Statement, Sublease Revenue			600
Rent expense related to non-cancelable operating leases					$ 3,500
Proceeds from Deferred Payment Obligations		$ 6,300	6,300
Debt Instrument, Repayable Upon Redemption, Preferred Stock						$ 5,900
Payments for loans			900
Deferred payment obligation			5,000
Payment of deferred payment obligation			2,000
Gain on extinguishment			3,000	$ 0	$ 0
Carrying value of equity securities transferred			5,500
Loss recognized			$ 3,300
Loss Contingency, Number of Defendants \| defendant	5
Number of active insurance policies \| insurance_policy			89	48
Reserves for known and incurred but not reported claims			$ 700	$ 500
Maximum
Loss Contingencies [Line Items]
Monthly base rent payments			400
Other Debt Obligations [Member]
Loss Contingencies [Line Items]
Debt Instrument, Amortized Cost		$ 6,300	6,270
Debt Instrument, Fair Value Disclosure			2,383
Fair Value, Inputs, Level 3 [Member] \| Other Debt Obligations [Member]
Loss Contingencies [Line Items]
Debt Instrument, Fair Value Disclosure			2,383
Fair Value, Debt Instrument, Valuation Techniques, Change in Technique, Quantification of Effect			$ 3,900

Commitments and Contingencies - Aggregate Future Non-Cancelable Minimum Lease Payments For Operating Leases (Details) $ in Thousands	Dec. 31, 2015 USD ($)
Commitments and Contingencies [Abstract]
2015	$ 4,284
2016	4,206
2017	4,273
2018	3,613
Total future non-cancelable minimum lease payments	16,376
Less: minimum payments to be received from non-cancelable subleases	(787)
Total future non-cancelable minimum operating lease payments, net	$ 15,589

Stockholder's Equity (Detail) - USD ($)	3 Months Ended								12 Months Ended
Stockholder's Equity (Detail) - USD ($)	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Aug. 31, 2008
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Document Period End Date									Dec. 31, 2015
Common stock authorized (in shares)	200,000,000				200,000,000				200,000,000	200,000,000
Common stock, par value per share (in dollars per share)	$ 0.0001				$ 0.0001				$ 0.0001	$ 0.0001
Preferred shares authorized (in shares)	10,000,000				10,000,000				10,000,000	10,000,000
Preferred stock par value per share (in dollars per share)	$ 0.0001				$ 0.0001				$ 0.0001	$ 0.0001
Additional shares of common stock reserved for issuance under the 2011 Plan (in shares)									1,000,000
Aggregate intrinsic value of stock options exercised									$ 6,800,000	$ 7,000,000	$ 13,500,000
Total fair value of stock options vested									3,300,000	6,200,000	9,100,000
Total fair value of RSUs vested									$ 14,400,000	$ 13,700,000	6,600,000
Shares withheld for tax withholdings (in shares)									354,446	325,292
Total payments for the employees’ minimum tax obligations to taxing authorities									$ 5,097,000	$ 4,928,000	$ 756,000
Stock-based compensation expense	$ 4,466,000	$ 4,603,000	$ 4,644,000	$ 3,881,000	$ 4,302,000	$ 4,486,000	$ 5,065,000	$ 3,803,000
Restricted stock units granted under equity award plans (in shares)									1,433,000
Stock Repurchase Program, Authorized Amount	75,000,000								$ 75,000,000
Stock Repurchased, Accumulated Value	26,175,000				$ 0				26,175,000	0
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate											0.00%
Stock-based compensation expense									2,900,000	5,400,000	$ 8,500,000
Unrecognized compensation cost related to unvested equity awards	1,100,000								$ 1,100,000
Weighted-average service period of unrecognized compensation cost related to unvested equity awards									7 months
Non-employee stock-based compensation expense									$ 0	0	$ 200,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate											0.93%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate											61.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value											$ 7.39
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense									14,200,000	11,600,000	$ 6,900,000
Unrecognized compensation cost related to unvested equity awards	$ 30,200,000								$ 30,200,000
Weighted-average service period of unrecognized compensation cost related to unvested equity awards									2 years 5 months
Non-employee stock-based compensation expense									$ 0	$ 0	$ 200,000
Performance-based restricted stock units with a market condition
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate										0.00%	0.00%
PBRSUs granted (in shares)									54,000	200,000	175,000
Stock-based compensation expense									$ 700,000	$ 800,000	$ 400,000.0
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate										1.11%	0.59%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate										48.00%	53.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value										$ 7.47	$ 6.39
2011 and 2008 Plan \| Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Grant Exercise Price, Percent of Fair Value									100.00%
2011 and 2008 Plan \| Incentive stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Grant Exercise Price, Percent of Fair Value									110.00%
Share-based Compensation Arrangement by Share-based Payment Award, Amount of Options Owned, Percent									10.00%
2011 and 2008 Plan \| Performance-based restricted stock units with a market condition
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Threshold Days									90 days
Share-based Compensation Arrangement by Share-based Payment Award, Price per Share on Grant Date Multiplier									1.25
2011 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	3,093,605								3,093,605		1,500,000
Additional shares of common stock reserved for issuance under the 2011 Plan (in shares)									1,000,000
2008 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)												9,019,474
Newly hired employees \| 2011 and 2008 Plan \| Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage									25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period									36 months
Newly hired employees \| 2011 and 2008 Plan \| Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage									25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period									3 years
Existing employees \| 2011 and 2008 Plan \| Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period									48 months
Existing employees \| 2011 and 2008 Plan \| Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period									4 years
Existing employees \| 2011 and 2008 Plan \| Performance-based restricted stock units with a market condition
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage									25.00%
Maximum \| 2011 and 2008 Plan \| Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Stock Options Exercise Period									10 years

Stockholder's Equity (Detail) - Activity Under Equity Award Plans And Related Information $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding (in shares)	2,685
Outstanding (in shares)	3,159
Outstanding (in shares)	3,264
Outstanding (in shares)	2,340
Outstanding (in dollars per share) \| $ / shares	$ 10.38
Outstanding (in dollars per share) \| $ / shares	$ 11.11
Shares authorized (in shares)	1,000
Options exercised (in shares)	(778)
Options exercised (in dollars per share) \| $ / shares	$ 6.44
Options forfeited (in shares)	(146)
Options forfeited (in shares)	146
Options forfeited (in dollars per share) \| $ / shares	$ 19.63
Restricted stock units granted (in shares)	(1,433)
Restricted stock units forfeited (in shares)	407
Outstanding (weighted-average contractual life)	5 years 2 months
Outstanding (intrinsic value) \| $	$ 4,430
Vested and exercisable
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested and exercisable (shares)	2,093
Vested and exercisable (in dollars per share) \| $ / shares	$ 11.44
Vested and exercisable (weighted-average contractual life)	5 years 2 months
Vested and exercisable (intrinsic value) \| $	$ 3,739
Vested and expected to vest
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested and expected to vest (shares)	2,327
Vested and expected to vest (in dollars per share) \| $ / shares	$ 11.13
Vested and expected to vest (weighted-average contractual life)	5 years 2 months
Vested and expected to vest (intrinsic value) \| $	$ 4,390

Stockholder's Equity (Detail) - Restricted Stock Unit Activity - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-vested units (in shares)	2,460
Non-vested units (in dollars per share)	$ 13.15
Granted (in shares)	1,433
Forfeited (in shares)	(407)
Non-vested units (in shares)	2,490	2,460
Non-vested units (in dollars per share)	$ 13.35	$ 13.15
Share-based compensation arrangement by share-based payment award, equity instruments other than options, nonvested, intrinsic value	$ 28,109
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted	54	200	175
Restricted stock units granted
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	1,433
Granted (in dollars per share)	$ 14.09
Restricted stock units vested
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)	(996)
Vested (in dollars per share)	$ 14.00
Restricted stock units forfeited
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Forfeited (in shares)	(407)
Forfeited (in dollars per share)	$ 13.29

Stockholder's Equity (Detail) - Weighted Average Assumptions To Estimate The Fair Value Of Equity Awards - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Document Period End Date	Dec. 31, 2015
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield			0.00%
Risk-free rate			0.93%
Expected volatility			61.00%
Expected term (in years)			6 years 1 month 5 days
Grant date fair value			$ 7.39
Performance-based restricted stock units with a market condition
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield		0.00%	0.00%
Risk-free rate		1.11%	0.59%
Expected volatility		48.00%	53.00%
Grant date fair value		$ 7.47	$ 6.39

Stockholder's Equity Stockholder's Equity (Detail) - Share Repurchase - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2013	Dec. 31, 2014
Equity Share Repurchase [Abstract]
Share Repurchase Utilized	1,993,000		0
Stock Repurchased, Accumulated, Weighted Average Price	$ 13.12		$ 0
Stock Repurchased, Accumulated Value	$ 26,175,000		$ 0
Stock Repurchased and Retired During Period, Shares	1,993,000
Stock Repurchased During Period Weighted Average Price	$ 13.12
Stock Repurchased During Period, Value	$ 26,175,000	$ 0

Income Taxes (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Contingency [Line Items]
Deferred Tax Assets, Valuation Allowance	$ 1,097,000	$ 0
Deferred Tax Assets, Net	(16,619,000)	(4,493,000)
Deferred Tax Liabilities, Net	0	(6,568,000)
Net operating loss carryforwards		3,336,000
Unrecognized tax benefits	5,315,000	3,707,000	$ 2,036,000	$ 1,136,000
Interest and penalties associated with unrecognized tax benefits	$ 400,000	681,000	$ 100,000
New Accounting Pronouncement, Early Adoption, Effect [Member]
Income Tax Contingency [Line Items]
Deferred Tax Assets, Net		$ 4,400,000

Income Taxes (Details) - Income Before Income Tax Provision - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Domestic									$ 65,445	$ 64,238	$ 64,281
International									54	44	14
Total income before income tax provision	$ 10,538	$ 12,676	$ 13,095	$ 29,190	$ 16,247	$ 17,258	$ 14,965	$ 15,812	$ 65,499	$ 64,282	$ 64,295

Income Taxes (Details) - Components Of The Provision For Income Taxes - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current
Federal									$ (23,456)	$ (26,517)	$ (17,145)
State									(2,790)	(3,031)	(1,188)
Foreign									(12,406)	(9,611)	(8,220)
Total current provision for income taxes									(38,652)	(39,159)	(26,553)
Deferred
Federal									12,022	13,668	2,920
State									553	550	121
Total deferred provision for income taxes									12,575	14,218	3,041
Total provision for income taxes	$ (5,011)	$ (4,842)	$ (5,065)	$ (11,159)	$ (6,998)	$ (6,425)	$ (5,566)	$ (5,952)	$ (26,077)	$ (24,941)	$ (23,512)

Income Taxes Income Taxes (Details) - Net Deferred Tax Liabilities - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Deferred revenue	$ 1,438,000	$ 2,779,000
Reserves and other	5,017,000	2,319,000
Stock-based compensation	5,701,000	5,963,000
Deferred Tax Assets, Goodwill and Intangible Assets	5,560,000	0
Total deferred tax assets	17,716,000	11,061,000
Valuation allowance	(1,097,000)	0
Net deferred tax assets	16,619,000	11,061,000
Deferred tax liabilities:
Depreciation and amortization	0	(6,568,000)
Deferred Tax Liabilities, Net	0	(6,568,000)
Net deferred taxes	$ 16,619,000	$ 4,493,000

Income Taxes Income Taxes (Details) - Reconciliation Of The Statutory Federal Income Tax To The Effective Tax - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Tax at statutory federal rate									$ (22,939)	$ (22,498)	$ (22,503)
State tax - net of federal benefit									(1,459)	(1,678)	(655)
Permanent differences									(663)	(879)	(569)
Foreign tax									(12,370)	(9,576)	(8,214)
Foreign tax credits									12,370	9,576	8,216
Foreign income not taxed at federal rate									(3)	(3)	1
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount									(1,097)	0	0
Other									84	117	212
Total provision for income taxes	$ (5,011)	$ (4,842)	$ (5,065)	$ (11,159)	$ (6,998)	$ (6,425)	$ (5,566)	$ (5,952)	$ (26,077)	$ (24,941)	$ (23,512)

Income Taxes Income Taxes (Details) - Unrecognized Tax Benefits - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax [Abstract]
Balance as of January 1,	$ 1,136	$ 3,707	$ 2,036	$ 1,136
Gross increase related to current period tax positions		1,606	1,672	1,043
Gross decrease related to prior period tax positions	$ 2		(1)	(143)
Balance as of December 31,		$ 5,315	$ 3,707	$ 2,036

Related-Party Transactions (Detail) $ in Thousands	12 Months Ended
Related-Party Transactions (Detail) $ in Thousands	Dec. 31, 2015 USD ($) board_member	Dec. 31, 2014 USD ($) board_member	Dec. 31, 2013 USD ($) board_member
Related Party Transaction [Line Items]
Number of Directors That Also Served On Client Boards \| board_member	4	5	4
Subscription fee revenue from related party transaction	$ 9,300	$ 9,400	$ 5,100
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party	300	200	$ 200
Receivables due from related parties	$ 0	$ 100

Employee Savings Plan Employee Savings Plan (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Employee Savings Plan [Abstract]
Defined Contribution Plan, Participation wait Period	3 months
Maximum employer contribution	$ 5,000	$ 5,000,000
Total matching contribution	$ 500,000	$ 400,000

Segment Reporting (Detail) - Revenue By Location - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
United States (in dollars)	$ 72,831	$ 68,212	$ 67,551	$ 83,287	$ 67,747	$ 65,407	$ 64,293	$ 61,888	$ 291,881	$ 259,335	$ 237,504
Total revenue (in dollars)	$ 72,831	$ 68,212	$ 67,551	$ 83,287	$ 67,747	$ 65,407	$ 64,293	$ 61,888	$ 291,881	$ 259,335	$ 237,504
Total revenue									100.00%	100.00%	100.00%
United States
United States (in dollars)									$ 186,439	$ 166,593	$ 145,310
United States									64.00%	64.00%	61.00%
Total revenue (in dollars)									$ 186,439	$ 166,593	$ 145,310
Korea
United States (in dollars)									$ 36,195	$ 36,849	$ 39,465
United States									12.00%	14.00%	17.00%
Total revenue (in dollars)									$ 36,195	$ 36,849	$ 39,465
Japan
United States (in dollars)									$ 28,319	$ 17,847	$ 12,552
Other foreign country									10.00%	7.00%	5.00%
Total revenue (in dollars)									$ 28,319	$ 17,847	$ 12,552
Other
United States (in dollars)									$ 40,928	$ 38,046	$ 40,177
Other foreign country									14.00%	15.00%	17.00%
Total revenue (in dollars)									$ 40,928	$ 38,046	$ 40,177

Subsequent Events (Details) - inventus Solutions Inc. [Member] - Subsequent Event [Member] $ in Millions	Jan. 22, 2016 USD ($)
Subsequent Event [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Business Combination, Consideration Transferred	$ 232

Selected Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013
Quarterly Financial Information Disclosure (Unaudited) [Abstract]
Revenue	$ 72,831	$ 68,212	$ 67,551	$ 83,287	$ 67,747	$ 65,407	$ 64,293	$ 61,888	$ 291,881	$ 259,335	$ 237,504
Cost of revenue	39,475	37,639	36,985	34,759	33,529	30,444	31,542	28,920	148,858	124,435	110,771
Selling, general and administrative expenses	20,199	18,773	18,997	19,459	18,059	17,786	18,579	17,255	77,428	71,679	62,525
(Gain) loss on sale of patent assets, net	0	0	(592)	0	0	(8)	(699)	0	(592)	(707)	126
Other Nonoperating Income (Expense)	(2,619)	876	934	121	16,159	17,185	14,871	15,713	(688)	354	213
Interest Income (Expense), Net					88	73	94	99
Income before provision for income taxes	10,538	12,676	13,095	29,190	16,247	17,258	14,965	15,812	65,499	64,282	64,295
Provision for income taxes	5,011	4,842	5,065	11,159	6,998	6,425	5,566	5,952	26,077	24,941	23,512
Net income	$ 5,527	$ 7,834	$ 8,030	$ 18,031	$ 9,249	$ 10,833	$ 9,399	$ 9,860	39,422	39,341	40,783
Net income available to common stockholders:
Basic									39,422	39,341	40,763
Diluted									$ 39,422	$ 39,341	$ 40,763
Net income available to common stockholders per common share(1):
Basic	$ 0.10	$ 0.14	$ 0.15	$ 0.33	$ 0.17	$ 0.20	$ 0.18	$ 0.19	$ 0.72	$ 0.74	$ 0.78
Diluted	$ 0.10	$ 0.14	$ 0.14	$ 0.33	$ 0.17	$ 0.20	$ 0.17	$ 0.18	$ 0.71	$ 0.72	$ 0.76
Other Data:
Deferred revenue, including current portion	$ 115,652				$ 136,209	$ 117,431	$ 142,623	$ 158,411	$ 115,652	$ 136,209		$ 112,820	$ 131,207	$ 140,534
Stock-based compensation expense	$ 4,466	$ 4,603	$ 4,644	$ 3,881	$ 4,302	$ 4,486	$ 5,065	$ 3,803

Segment Reporting (Detail)	12 Months Ended
Segment Reporting (Detail)	Dec. 31, 2015
Segment Reporting
Number of reportable segments	1