Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2018	Apr. 27, 2018
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q1
Entity Trading Symbol	RPXC
Entity Registrant Name	RPX Corporation
Entity Central Index Key	0001509432
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		49,933,908

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 159,220	$ 138,710
Short-term investments	9,027	18,455
Restricted cash	192	249
Accounts receivable, net	77,485	63,860
Prepaid expenses and other current assets	26,228	34,398
Total current assets	272,152	255,672
Patent assets, net	119,619	131,888
Property and equipment, net	5,025	5,090
Intangible assets, net	47,716	49,087
Goodwill	72,511	70,756
Restricted cash, less current portion	968	968
Deferred tax assets	27,257	27,939
Other assets	18,985	20,233
Total assets	564,233	561,633
Current liabilities:
Accounts payable	3,610	2,225
Accrued liabilities	11,011	15,736
Deferred revenue	89,246	85,790
Other current liabilities	2,115	1,485
Total current liabilities	105,982	105,236
Deferred revenue, less current portion	349	484
Deferred tax liabilities	3,697	3,657
Other liabilities	11,012	11,104
Total liabilities	121,040	120,481
Commitments and contingencies (Note 11)
Stockholders’ equity:
Common stock	5	5
Additional paid-in capital	378,748	376,793
Retained earnings	68,390	70,808
Accumulated other comprehensive loss	(3,950)	(6,454)
Total stockholders’ equity	443,193	441,152
Total liabilities and stockholders’ equity	$ 564,233	$ 561,633

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Revenue	$ 67,121	$ 75,415
Cost of revenue	42,230	44,130
Selling, general and administrative expenses	24,252	21,728
Operating income	639	9,557
Interest income	327	165
Interest expense	(11)	(908)
Other income (expense), net	546	210
Total interest and other income (expense), net	862	(533)
Income before provision for income taxes	1,501	9,024
Provision for income taxes	1,421	3,369
Net income	$ 80	$ 5,655
Net income per share:
Basic (dollars per common share)	$ 0.00	$ 0.12
Diluted (dollars per common share)	$ 0.00	$ 0.11
Weighted-average shares used in computing net income per share:
Basic (in shares)	49,755	48,676
Diluted (in shares)	50,267	49,305
Cash dividend (in usd per share)	$ 0.05	$ 0.00

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 80	$ 5,655
Other comprehensive income, net of tax:
Unrealized holding gains on available-for-sale securities arising during the period, net of tax	4	51
Foreign currency translation adjustments	2,500	928
Comprehensive income	$ 2,584	$ 6,634

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Cash Flows [Abstract]
Cash and Cash Equivalents, at Carrying Value	$ 159,220	$ 158,323
Operating activities
Net income	80	5,655
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	32,593	35,731
Stock-based compensation	3,690	2,734
Amortization of premium on investments	68	471
Deferred income taxes	580	1,911
Unrealized foreign currency gain	(751)	(169)
Other	81	141
Changes in assets and liabilities:
Accounts receivable	(13,126)	31,933
Prepaid expenses and other assets	9,543	(7,716)
Accounts payable	1,348	(819)
Accrued and other liabilities	(4,259)	(5,624)
Deferred revenue	3,320	6,996
Net cash provided by operating activities	33,167	71,244
Investing activities
Purchases of investments	(3,250)	(3,875)
Maturities of investments	12,515	25,875
Purchases of property and equipment	(731)	(362)
Acquisitions of patent assets	(17,321)	(27,421)
Net cash used in investing activities	(8,787)	(5,783)
Financing activities
Repayment of principal on term debt	0	(1,250)
Proceeds from exercise of stock options	142	422
Taxes paid related to net-share settlements of restricted stock units	(1,895)	(1,708)
Payments of capital leases	(38)	(104)
Payments of dividends to stockholders	(2,498)	0
Repurchase of common stock	0	(4,491)
Net cash used in financing activities	(4,289)	(7,131)
Foreign-currency effect on cash, cash equivalents, and restricted cash	362	35
Net increase in cash, cash equivalents, and restricted cash	20,453	58,365
Cash, cash equivalents, and restricted cash at beginning of period	139,927	101,576
Cash, cash equivalents, and restricted cash at end of period	160,380	159,941
Non-cash investing and financing activities
Change in patent assets purchased and accrued but not paid	0	250
Change in fixed assets purchased and accrued but not paid	0	(46)
Restricted Cash and Cash Equivalents, Current	192	653
Restricted Cash and Cash Equivalents, Noncurrent	$ 968	$ 965

Nature of Business	3 Months Ended
Nature of Business	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature Of Business	Nature of Business RPX Corporation (also referred to herein as “RPX” or the “Company”) helps companies reduce patent litigation risk and corporate legal expense through two primary service offerings: its patent risk management services and its discovery services. The Company's patent risk management services help companies reduce patent-related risk and expense through subscription-based services that facilitate more efficient exchanges of value between owners and users of patents compared to transactions driven by actual or threatened litigation. The Company’s patent risk management membership clients pay an annual subscription fee and in return, receive access to substantially all of the Company's patent portfolio as well as an array of services provided throughout their membership. Access to these services is available primarily through discussions with the Company's professionals—particularly client services and its team of patent experts, as well as through a proprietary database, and attendance at periodic conferences. In addition to its subscription-based patent risk management services, the Company underwrites patent infringement liability insurance policies to insure against certain costs of litigation. The Company uses a reinsurance subsidiary company to assume a portion of the underwriting risk on the insurance policies that the Company issues on behalf of third party underwriters. To date, the effect of the insurance policies that the Company has assumed through its reinsurance business has not been material to the Company’s results of operations, financial condition, or cash flows. In January 2016, the Company acquired Inventus Solutions, Inc. ("Inventus"), now a wholly owned subsidiary of the Company, and began offering its discovery services, which consist of technology-enabled services to assist law firms and corporate legal departments manage costs and risks related to the legal discovery process. The Company's discovery services include data hosting and backup, data processing and collection, project management, document review, and traditional document production. All of these services are designed to streamline the administration of litigation, investigations, and regulatory compliance.

Basis of Presentation and Significant Accounting Policies

3 Months Ended

Mar. 31, 2018

Accounting Policies [Abstract]

Basis Of Presentation And Significant Accounting Policies

Basis of Presentation and Significant Accounting Policies

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States of America and with the instructions for Form 10-Q and Regulation S-X for interim financial statements. Accordingly, they do not include all of the information and notes required for complete financial statements. In the opinion of management, all adjustments, consisting of normal recurring items, necessary to state fairly the results of the interim periods have been included in the accompanying financial statements. Operating results for the three months ended March 31, 2018 are not necessarily indicative of the results that may be expected for any subsequent interim period or for the year ending December 31, 2018. The unaudited condensed consolidated financial statements should be read in conjunction with the audited financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 which was filed with the U.S. Securities and Exchange Commission (“SEC”) on March 5, 2018.

Significant Accounting Policies

Other than the revised revenue recognition policy under Accounting Standards Codification ("ASC") 606, Revenue from Contracts with Customers ("ASC 606") for the patent risk management segment disclosed below, there have been no material changes to the Company’s significant accounting policies during the three months ended March 31, 2018, as compared to the significant accounting policies presented under the heading “Basis of Presentation and Significant Accounting Policies” in Note 2 of the Notes to Consolidated Financial Statements in Part II, Item 8 of the Company’s Annual Report on Form 10-K filed with the SEC on March 5, 2018.

Revenue Recognition

Patent Risk Management

The primary source of the Company’s revenue from its patent risk management services offering is fees paid by its clients under subscription agreements. From these arrangements, the Company recognizes subscription revenue for providing ongoing services that mitigate or eliminate the costs of patent litigation throughout the membership term, and licensing revenue for certain discrete patent assets transferred to its membership clients (“catalyst license”) as well as for access to the patent portfolio that clients obtain when becoming a member or renewing membership (“portfolio access license”). Each of these promises are generally capable of being distinct and are accounted for as a separate performance obligation. Revenue is recognized when control of these products and services are transferred to the customer, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those services.

Nature of Products and Services:


•	Subscription Revenue

Members pay annual fees over the term of their membership for the Company to provide ongoing services, including the acquisition of patent assets, that mitigate or eliminate the costs of patent litigation. The Company reduces a member’s risk and expense by defensively acquiring or licensing patent assets on a continual basis throughout the membership term. The Company also provides extensive patent market intelligence and patent-related data to its clients as part of its patent risk management service. The nature of the Company’s promise is a stand-ready obligation to provide an array of patent risk management services that are each capable of being distinct. The Company’s patent risk management services are accounted for as a series of distinct services and revenue is recognized over time as the customer simultaneously receives and consumes the benefits provided as the Company performs the patent risk management services.


•	Fee Revenue

•

Catalyst license fee - The Company’s subscription agreements can include certain discrete patent licenses that a member receives at the start of their membership term which are often catalysts for joining or renewing a member’s patent risk management subscription. This catalyst license provides the member with a right to use the intellectual property as it exists when it's made available to the member. Members receive either a perpetual license or term license which provide members with the same functionality and differ mainly in the duration over which the member benefits from the license. Catalyst licenses are a right to use the intellectual property and are recognized upfront at the point in time when the license is made available to the member. The Company may treat the fee allocated to the catalyst license on a gross or net basis against patent assets depending on the specific facts and circumstances of the transaction and only capitalizes the acquired asset that relates to non-contributing members which were not recognized on a net basis.

•

Portfolio access license fee - Members receive a term license to all the patent assets owned by the Company upon joining as a member, which converts to a perpetual license when a member vests, which is generally after two or three years. Members will also vest into perpetual license rights to the Company's patent assets acquired throughout the membership term on a rolling basis. In the event a member does not renew its patent risk management subscription, the member retains license rights only to those patent assets into which it has perpetually vested. This portfolio license is a right to use the intellectual property and is recognized at a point in time when the portfolio access for the unvested licenses is made available to the member which is typically at the start of the respective membership term.

•

Other fee-related revenue - The Company's syndicated acquisitions can include member or non-member fees for the sale of perpetual licenses that are separate from fees paid under subscription agreements and are not catalysts for membership. The Company may treat these on a gross or net basis against patent assets depending on the specific facts and circumstances of the transaction. The Company may also recognize revenue from advisory fees in connection with certain syndicated acquisitions. The sale of perpetual licenses and advisory fees are collectively referred to as other fee-related revenue.

Significant Judgments:

Judgment is required to determine the standalone selling price (“SSP”) for each distinct performance obligation. The Company utilizes a multi-step process to estimate the standalone selling price for each of its performance obligations. The Company does not sell any of its patent risk management subscription services on a standalone basis and each member is priced based on member specific factors related to their individual patent litigation risk. The Company considers all available information (including market conditions, member specific factors and information about the members exposure to litigation risk and cost) when estimating SSP. In certain arrangements, the Company will use the residual method to determine SSP as there is a high degree of variability in the prices charged for the Company’s products and services since each client has a unique patent risk profile.

Each client’s annual subscription fee is based either on a rate card in effect at the time of the client’s initial membership agreement or through a fixed fee which is risk-adjusted based on the client's unique patent risk profile. A client’s subscription fee on rate card is generally determined using its 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. For members on rate card, the Company must estimate the total transaction price at contract execution as financial data for future years is unavailable to input into the rate card calculation. The Company uses the rate card fee for the current year to estimate the membership fees for future membership terms in its determination of the total transaction price. The Company allocates this variable consideration entirely to the series of patent risk management services for the respective year and updates its estimate of the transaction price annually upon billing.

As part of the adoption of ASC 606, the Company elected to use the following practical expedients:


•	for completed contracts at transition that have variable consideration, the Company will use the transaction price at the date the contract was completed, rather than estimating variable consideration amounts in the comparative periods,


•	for contracts modified prior to January 1, 2016, the Company will reflect the aggregate effect of all modifications that occur before January 1, 2016 when identifying the satisfied and unsatisfied performance obligations, determining the transaction price and allocating the transaction price to the satisfied an unsatisfied performance obligations for the modified contract at transition, and


•	the Company will not adjust the promised amount of consideration for the effects of a significant financing component when the Company expects, at contract inception, that the period between the Company's transfer of a promised product or service to a customer and when the customer pays for that product or service will be one year or less.

Contract Balances:

The timing of revenue recognition, billings and cash collections results in unbilled trade receivables (recognized in Accounts receivable, net in the Company's consolidated balance sheet) as well as deferred revenues. The Company records an unbilled receivable when revenue is recognized prior to invoicing, or deferred revenue when revenue is recognized subsequent to invoicing. For multi-year agreements, members are generally invoiced annually on the anniversary date of the agreement. The Company records an unbilled receivable related to revenue recognized for the portfolio access licenses and catalyst licenses and deferred revenue for the unrecognized portion of its patent risk management services.

For certain catalyst licenses which are recorded on a net basis, the Company records a non-trade receivable (recognized in Other assets in the Company's consolidated balance sheet) as the transaction results in a reduction of basis in the Company's acquired patent asset.

In instances where the timing of revenue recognition differs from the timing of invoicing, the Company determined its contracts generally do not include a significant financing component. The primary purpose of its invoicing terms is to provide customers with simplified and predictable ways of purchasing its products and services, not to receive financing from its customers, or to provide its customers with financing, such as catalyst and portfolio licenses that are invoiced annually with revenue recognized upfront.

The opening balance of current and long-term trade and non-trade unbilled receivables was $54.2 million as of January 1, 2016.

Recent Accounting Pronouncements

In November 2016, the Financial Accounting Standards Board "(FASB") issued Accounting Standards Update No. 2016-18, Statement of Cash Flows (Topic 230), Restricted Cash ("ASU 2016-18"). ASU 2016-18 addresses the diversity in practice that exists in the classification and presentation of changes in restricted cash and requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. The guidance is effective retrospectively for fiscal years beginning after December 15, 2017. The Company adopted this guidance effective January 1, 2018, using the retrospective transition approach for all periods presented. The adoption of ASU 2016-18 does not have a material impact on the Company's consolidated financial statements.

In February 2016 the FASB issued ASU 2016-02, Leases (Topic 842) (“ASU 2016-02”), which requires lessees to put most leases on their balance sheets but recognize the expenses on their income statements in a manner similar to current practice. ASU 2016-02 states that a lessee would recognize a lease liability for the obligation to make lease payments and a right-to-use asset for the right to use the underlying asset for the lease term. The new standard is effective for interim and annual periods beginning after December 15, 2018 and early adoption is permitted. The Company's leases are primarily operating leases for office space and will continue to be classified as operating leases under ASC 2016-02. The Company is currently evaluating the impact of this guidance on its consolidated financial statements.

Revenue from Contracts with Customers

Effective January 1, 2018, the Company began recognizing revenue in accordance with ASC 606 under which revenue is recognized when a customer obtains control of promised goods or services in an amount that reflects the consideration the entity expects to receive in exchange for those goods or services. In addition, ASC 606 requires disclosure of the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers.

The Company adopted the standard using the full retrospective method to recast each prior reporting period presented.

The new standard’s most significant impact to the Company’s financial information relates to the identification of multiple performance obligations from its patent risk management membership subscription and the timing and amount of recognition for these separable performance obligations. Specifically, the Company recognizes separate performance obligations under ASC 606 for certain discrete patent assets transferred to its membership clients as well as for access to the patent portfolio that clients obtain when becoming a member or renewing membership. The revenue generated from these additional performance obligations is recognized at a point in time under ASC 606. Formerly, under ASC 605, the Company generally recognized membership fees ratably on a gross basis over the term of the customer contract. Therefore, the adoption of ASC 606 increases the variability of revenue recognized from the Company's patent risk management services from period to period as well as reduces revenue and patent assets, and related amortization of these patent assets, previously treated on a gross basis under ASC 605 that are treated on a net basis against patent assets under ASC 606 due to the additional separable performance obligations.

ASC 606 also requires the Company to make significant judgments in determining SSP for each distinct performance obligation. The Company’s patent licenses are not sold or priced separately from its patent risk management service and are sold at a broad range of amounts which is in the form of a bundled membership fee. The Company typically has more than one SSP for the same licenses and services based on a member’s individual perceived patent risk. As such, the Company is required to determine SSP using inputs that are not directly observable. The Company considers all information that is available and maximizes the use of observable inputs in its determination of SSP.

Revenue recognition related to the Company’s discovery services segment and its patent risk management insurance offering is not materially changed under ASC 606.

The Company recast its financial statements from amounts previously reported due to the adoption of ASC 606 shown below.



RPX Corporation
Consolidated Statements of Operations
Selected Line Items Under ASC 605 and ASC 606
(in thousands)
(unaudited)
	Three months ended March 31, 2017
	ASC 605		New Revenue Standard Adjustment			ASC 606
Revenue	$	82,512	$	(7,097	)	$	75,415
Cost of revenue	51,298		(7,168		)	44,130
Selling, general and administrative expenses	21,121		607			21,728
Provision for income taxes	3,567		(198		)	3,369
Net income	$	5,993	$	(338	)	$	5,655



RPX Corporation
Consolidated Balance Sheet
Selected Line Items Under ASC 605 and ASC 606
(in thousands)
(unaudited)
	December 31, 2017
	ASC 605		New Revenue Standard Adjustment			ASC 606
Accounts receivable, net	$	51,544	$	12,316		$	63,860
Prepaid expenses and other current assets	25,687		8,711			34,398
Patent assets, net	163,048		(31,160		)	131,888
Deferred tax assets	23,572		4,367			27,939
Other assets	3,664		16,569			20,233
Deferred revenue, current	105,150		(19,360		)	85,790
Deferred revenue, less current portion	1,718		(1,234		)	484
Retained earnings	$	39,411	$	31,397		$	70,808



RPX Corporation
Consolidated Statements of Cash Flows
Selected Line Items Under ASC 605 and ASC 606
(in thousands)
(unaudited)
	Three months ended March 31, 2017
	ASC 605			New Revenue Standard Adjustment			ASC 606
Operating activities
Net income	$	5,993		$	(338	)	$	5,655
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	42,929			(7,198		)	35,731
Deferred income taxes	2,109			(198		)	1,911
Other	(484		)	625			141
Changes in assets and liabilities:
Accounts receivable	27,815			4,118			31,933
Prepaid expenses and other assets	(5,572		)	(2,144		)	(7,716		)
Deferred revenue	5,819			1,177			6,996

Investing activities
Acquisitions of patent assets	$	(31,379	)	$	3,958		$	(27,421	)

In addition, the cumulative effect of ASC 606 to the Company’s retained earnings at January 1, 2016 was an increase of $44.8 million.

Net Income Per Share

3 Months Ended

Mar. 31, 2018

Earnings Per Share [Abstract]

Net Income Per Share

sic and diluted net income per share are computed by dividing net income by the weighted-average number of shares of common stock outstanding during the period. Diluted net income per share is computed by using the weighted-average number of shares of common stock outstanding during the period, including potentially dilutive shares. Potentially dilutive shares include outstanding stock options and restricted stock units ("RSUs"). The dilutive effect of potentially dilutive shares is reflected in diluted earnings per share by application of the treasury stock method. Under the treasury stock method, an increase in the fair value of the Company's common stock can result in a greater dilutive effect from potentially dilutive shares.

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



	Three Months Ended March 31,
	2018		2017
Numerator:
Net income	$	80	$	5,655
Denominator:
Basic shares:
Weighted-average shares used in computing basic net income per share	49,755		48,676
Diluted shares:
Weighted-average shares used in computing basic net income per share	49,755		48,676
Dilutive effect of stock options and restricted stock units using the treasury-stock method	512		629
Weighted-average shares used in computing diluted net income per share	50,267		49,305
Net income per share:
Basic	$	—	$	0.12
Diluted	$	—	$	0.11

The following securities were not included in the calculation of diluted shares outstanding as the effect would have been anti-dilutive (in thousands):



	Three Months Ended March 31,
	2018	2017
Outstanding weighted-average:
Stock options	582	718
Restricted stock units	562	765

Financial Instruments

3 Months Ended

Mar. 31, 2018

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):



	March 31, 2018
	Amortized Cost		Unrealized					Estimated Fair Value		Level 1		Level 2
	Amortized Cost		Gains		Losses			Estimated Fair Value		Level 1		Level 2
Cash equivalents:
Commercial paper	$	16,230	$	—	$	—		$	16,230	$	—	$	16,230
Money market funds	57,969		—		—			57,969		57,969		—
Municipal bonds	2,251		—		—			2,251		—		2,251
U.S. government and agency securities	25,974		—		—			25,974		—		25,974
	$	102,424	$	—	$	—		$	102,424	$	57,969	$	44,455
Short-term investments:
Municipal bonds	$	9,032	$	—	$	(5	)	$	9,027	$	—	$	9,027



	December 31, 2017
	Amortized Cost		Unrealized					Estimated Fair Value		Level 1		Level 2
	Amortized Cost		Gains		Losses			Estimated Fair Value		Level 1		Level 2
Cash equivalents:
Commercial paper	$	13,035	$	—	$	—		$	13,035	$	—	$	13,035
Corporate bonds	1,205		—		—			1,205		—		1,205
Money market funds	52,267		—		—			52,267		52,267		—
Municipal bonds	13,060		—		—			13,060		—		13,060
U.S. government and agency securities	13,101		—		—			13,101		—		13,101
	$	92,668	$	—	$	—		$	92,668	$	52,267	$	40,401
Short-term investments:
Commercial paper	$	1,994	$	—	$	—		$	1,994	$	—	$	1,994
Corporate bonds	3,074		—		(3		)	3,071		—		3,071
Municipal bonds	11,888		—		(3		)	11,885		—		11,885
U.S. government and agency securities	1,508		—		(3		)	1,505		—		1,505
	$	18,464	$	—	$	(9	)	$	18,455	$	—	$	18,455

The Company's financial investments are generally classified as available-for-sale. Available-for-sale securities 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 loss. Realized gains and losses on these securities are included in other income (expense), net in the Company’s condensed consolidated statements of operations and have not been material for all periods presented.

As of March 31, 2018 and December 31, 2017, approximately 100% of the Company's marketable security investments mature within one year and nil mature within one to five years. As of March 31, 2018, no individual security incurred continuous unrealized losses for greater than 12 months.

- 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

Contract Balances

3 Months Ended

Mar. 31, 2018

Revenue from Contract with Customer [Abstract]

Contract Balances

Timing of revenue recognition may differ from the timing of invoicing to customers for the Company's patent risk management services. The Company records an unbilled receivable when revenue is recognized prior to invoicing and deferred revenue when revenue is recognized subsequent to invoicing. For multi-year agreements, the Company generally invoices members annually on the anniversary date of the agreement and when applicable, records an unbilled receivable related to portfolio access or catalyst licenses when revenue is recognized in excess of billings since it has an unconditional right to invoice and receive future payments related to these licenses.

For certain catalyst licenses which are recorded on a net basis, the Company records a non-trade receivable in prepaid expenses and other current assets or other assets in the Company's consolidated balance sheet.

The Company's unbilled receivables and deferred revenue from contracts with customers consisted of the following (in thousands):



	March 31, 2018			December 31, 2017
Accounts receivable, net:
Unbilled trade receivables, current	$	10,192		$	12,316
Prepaid expenses and other current assets:
Unbilled non-trade receivables, current	8,021			8,711
Other assets:
Unbilled trade receivables, non-current	6,076			7,684
Unbilled non-trade receivables, non-current	8,923			8,884
Deferred revenue, current	(89,246		)	(85,790		)
Deferred revenue, non-current	(349		)	(484		)
Total deferred revenue, net	$	(56,383	)	$	(48,679	)

The Company has not recorded any impairment losses on its receivables to date. During the three months ended March 31, 2018 and 2017, the Company recognized revenue of $32.7 million and $35.4 million, respectively, which was included in deferred revenue in the Company's consolidated balance sheets at December 31, 2017 and 2016, respectively.

Revenue allocated to remaining performance obligations represent contracted revenue that has not yet been recognized, which includes unearned revenue and amounts that the Company will invoice and recognize as revenue in future periods. The Company's unfulfilled performance obligations as of March 31, 2018 and the estimated revenue expected to be recognized in the future related to the performance obligations are as follows (in thousands):



2018 (remainder)	$	104,093
2019	72,415
2020	25,616
2021	2,209
2022	1,255
Thereafter	968
Total unfulfilled performance obligations	$	206,556

Patent Assets, Net

3 Months Ended

Mar. 31, 2018

Patent Assets, Net [Abstract]

Patent Assets, Net

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



	December 31, 2017			Additions			Disposals			March 31, 2018
Patent assets	$	889,188		$	17,321		$	(8,232	)	$	898,277
Accumulated amortization	(757,300		)	(29,483		)	8,125			(778,658		)
Patent assets, net	$	131,888								$	119,619

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 patent asset portfolio on a straight-line basis over its estimated economic useful life. As of March 31, 2018, the estimated economic useful lives of the Company’s patent assets generally ranged from 24 to 60 months. As of March 31, 2018, the weighted-average estimated economic useful life at the time of acquisition of all patent assets acquired since the Company’s inception was 38 months. Patent assets acquired during the three months ended March 31, 2018 had a weighted-average estimated economic useful life at the time of acquisition of 25 months.

As of March 31, 2018, the Company expects amortization expense in future periods to be as follows (in thousands):



2018 (remainder)	$	65,297
2019	42,951
2020	11,282
2021	89
Total estimated future amortization expense	$	119,619

Amortization expense related to the Company's patent assets was $29.6 million and $32.6 million for the three months ended March 31, 2018 and 2017, respectively.

Property and Equipment, Net

3 Months Ended

Mar. 31, 2018

Property, Plant and Equipment, Net, by Type [Abstract]

Property and Equipment, Net

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



	March 31, 2018			December 31, 2017
Internal-use software	$	8,729		$	8,530
Leasehold improvements	2,098			2,098
Computer, equipment and software	6,558			5,960
Furniture and fixtures	755			755
Construction-in-progress	25			21
Total property and equipment, gross	18,165			17,364
Less: Accumulated depreciation and amortization	(13,140		)	(12,274		)
Total property and equipment, net	$	5,025		$	5,090

Depreciation and amortization expense related to the Company's property and equipment was $0.8 million for each three month period ended March 31, 2018 and 2017.

Goodwill

3 Months Ended

Mar. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill

The changes in the carrying amounts of goodwill by operating segment were as follows (in thousands):



	Patent Risk Management		Discovery Services		Total
Balance as of December 31, 2017	$	19,978	$	50,778	$	70,756
Foreign currency translation adjustments	—		1,755		1,755
Balance as of March 31, 2018	$	19,978	$	52,533	$	72,511

The Company reviews goodwill for impairment at least annually or more frequently if events or changes in circumstances indicate that the carrying value of goodwill may not be recoverable. No impairment of goodwill was identified during the three months ended March 31, 2018.

Intangible Assets, Net

3 Months Ended

Mar. 31, 2018

Intangible Assets, Net (Excluding Goodwill) [Abstract]

Intangible Assets, Net

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



	March 31, 2018							December 31, 2017
	Carrying Amount		Accumulated Amortization			Net Carrying Amount		Carrying Amount		Accumulated Amortization			Net Carrying Amount
Customer relationships	$	57,605	$	(13,553	)	$	44,052	$	56,688	$	(11,764	)	$	44,924
Trademarks	2,900		(1,058		)	1,842		2,900		(938		)	1,962
Developed technology	6,435		(4,613		)	1,822		6,237		(4,036		)	2,201
	$	66,940	$	(19,224	)	$	47,716	$	65,825	$	(16,738	)	$	49,087

As of March 31, 2018, the Company expects amortization expense in future periods to be as follows (in thousands):



2018 (remainder)	$	6,540
2019	6,739
2020	6,615
2021	6,615
2022	6,160
Thereafter	15,047
Total estimated future amortization expense	$	47,716

Amortization expense related to the Company's intangible assets was $2.2 million and $2.3 million for the three months ended March 31, 2018 and 2017, respectively.

Commitments and Contingencies

3 Months Ended

Mar. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Commitments

The Company generally does not enter into long-term minimum purchase commitments. Its principal long-term commitments consist of obligations under operating leases for office space. There were no material changes to the Company’s contractual obligations or commitments during the three months ended March 31, 2018 as compared to those presented under the heading “Commitments and Contingencies” in Note 12 of the Notes to Consolidated Financial Statements in Part II, Item 8 of the Company’s Annual Report on Form 10-K filed with the SEC on March 5, 2018.

The following table summarizes rent expense related to non-cancelable operating leases (in millions):



	Three Months Ended March 31,
	2018			2017
Rent expense	$	1.4		$	1.6
Sublease income	(0.3		)	(0.3		)
Rent expense, net of sublease income	$	1.1		$	1.3

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 litigation or contingencies was recorded as of March 31, 2018 or December 31, 2017.

In June 2013, Kevin O’Halloran, as Trustee of the Liquidating Trust of Tectonics, 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 to the U.S. District Court for the Middle District of Florida. In August 2016, the District Court affirmed the judgment in favor of the Defendants. In September 2016, the Debtor filed an appeal of the judgment to the U.S. Court of Appeals for the Eleventh Circuit. The appellate briefing was completed in January 2017, and oral argument occurred on December 14, 2017. 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 significant 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. No liability was recorded for these agreements as of March 31, 2018 or December 31, 2017. 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.

As part of the Company's discovery services offering, the Company generally warrants that it will perform the services in good faith and in a timely and professional manner, and that it will exercise the same level of professional care commonly found in the industry. Additionally, the Company has agreed to provisions for indemnifying customers against liabilities if its discovery services infringe a third party’s intellectual property rights or if it breaches agreed privacy, security and/or confidentiality obligations. To date, the Company has not incurred any material costs, and it has not accrued any liabilities in the accompanying condensed consolidated financial statements, as a result of these obligations. The Company also enters into service-level agreements with its discovery services clients that specify required levels of application uptime and may permit customers to receive credits or to terminate their agreements in the event that the Company fails to meet required performance levels. To date, the Company has not experienced any significant failures to meet defined levels of performance and, as a result, has not accrued any liabilities related to these agreements in its condensed consolidated financial statements.

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

The Company offers patent litigation insurance that covers certain costs associated with patent infringement lawsuits, and it assumes a portion of the underwriting risk on these insurance policies that it issues on behalf of third party underwriters. As of March 31, 2018 and December 31, 2017, the Company recorded a reserve of $0.9 million and $1.1 million, respectively, for known and incurred but not reported claims that represent estimated claim costs and related expenses for the policies underwritten and its portion of the underwriting risk on policies that the Company issued on behalf of third party underwriters. The Company regularly reviews loss reserves using a variety of actuarial techniques and updates them as its loss experience develops.

Stockholders' Equity

3 Months Ended

Mar. 31, 2018

Stockholders Equity and Share-based Compensation [Abstract]

Stockholders' Equity

Stockholders’ Equity

Equity Plans

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, 2017	4,728		979		$	13.29
Options exercised	—		(39	)	3.61
Options forfeited/canceled	200		(200	)	14.91
Restricted stock units granted	(648	)	—		—
Restricted stock units forfeited	110		—		—
Restricted stock units withheld related to net-share settlement of restricted stock units	146		—		—
Balance - March 31, 2018	4,536		740		13.36		3.0	$	1,129
Vested and exercisable - March 31, 2018			740		13.36		3.0	1,129

The aggregate intrinsic value of stock options exercised during the three months ended March 31, 2018 and 2017 was $0.3 million and $0.7 million, respectively. No stock options vested during the three months ended March 31, 2018, and as of March 31, 2018, all options issued and outstanding were fully vested.

Restricted Stock Units

The summary of RSU activity, which includes performance-based restricted stock units (“PBRSUs”), is as follows (in thousands, except per share data):



	Number of Shares		Weighted-Average Grant Date Fair Value		Aggregate Intrinsic Value
Non-vested units - December 31, 2017	2,520		$	11.95
Granted	648		13.43
Vested	(413	)	12.42
Forfeited	(110	)	11.93
Non-vested units - March 31, 2018	2,645		12.15		$	28,273

The total grant date fair value of RSUs vested during the three months ended March 31, 2018 and 2017 was $5.4 million and $4.4 million, respectively.

In October 2013, the Board of Directors approved net-share settlement for tax withholdings on RSU vesting. During the three months ended March 31, 2018, the Company withheld issuing 146,002 shares of its common stock based on the value of the RSUs on their vesting dates as determined by the Company’s closing common stock price. Total payments to taxing authorities for employees’ minimum tax obligations were $1.9 million for the three months ended March 31, 2018, and were recorded as a reduction to additional paid-in capital and reflected as a financing activity within the condensed 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 fair value of RSUs granted to employees and directors is measured by reference to the fair value of the underlying shares on the date of grant. Stock-based compensation expense which was related to PBRSUs and RSUs granted to employees and directors was $3.6 million and $2.7 million for the three months ended March 31, 2018 and 2017, respectively. The Company did not grant any PBRSUs during either three-month period ended March 31, 2018 or 2017.

As of March 31, 2018, there was $29.1 million of unrecognized compensation cost related to RSUs, including PBRSUs, which is expected to be recognized over a weighted-average period of 2.8 years. Future grants of equity awards will increase the amount of stock-based compensation expense to be recorded.

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. In March 2016 and May 2016, the Company increased its share repurchase program by $25.0 million and $50.0 million, respectively, for a total amount authorized of $150.0 million. As of March 31, 2018, the Company repurchased $94.6 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 but was suspended upon the Company's entry into the Merger Agreement as described in Note 16, "Subsequent Events" and may be modified or terminated 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 is reflected as a reduction to common stock and retained earnings in the Company's consolidated balance sheet. Share repurchase activity during the period presented was as follows (in thousands, except per share data):



	Shares Repurchased	Average Price per Share		Value of Shares Repurchased
Cumulative repurchase activity as of December 31, 2017	8,617	$	10.97	$	94,566
Repurchase activity during the period	—	—		—
Cumulative repurchase activity as of March 31, 2018	8,617	$	10.97	$	94,566

Dividends

During the three months ended March 31, 2018, the Company declared and paid quarterly cash dividends of $2.5 million, or $0.05 per share of common stock. The Company's quarterly dividend was canceled in April 2018 upon the Company's entry into the Merger Agreement as described in Note 16, "Subsequent Events".

- 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 310
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 4.E)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74567-122707

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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-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 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(e))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 6: 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(31))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 4.C)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770

Reference 8: 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(30))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 10: 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))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6405834&loc=d3e23285-112656

Reference 13: 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 14: 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 15: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 16: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21564-112644

+ Details

Income Taxes	3 Months Ended
Income Taxes	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company uses an estimated annual effective tax rate based upon a projection of its annual fiscal year results to measure the income tax benefit or expense recognized in each interim period. The Company’s effective tax rate, including the impact of discrete items, was 95% and 37% for the three months ended March 31, 2018 and 2017, respectively. The Company's effective tax rate for the three months ended March 31, 2018 increased as compared to the prior year and as compared to the statutory tax rate primarily due to the impact of foreign tax withholdings under the Tax Cuts and Jobs Act. On December 22, 2017, the Tax Cuts and Jobs Act was signed into law. Among other changes was a permanent reduction in the federal corporate income tax rate from 35% to 21% as well as a change in the US international tax system to move towards a more territorial system. As a result, Global Intangible Low-Taxed Income ("GILTI") was implemented to discourage the erosion of the US tax base through the movement of intangible assets offshore. As of March 31, 2018, the amounts recorded for the Tax Cuts and Jobs Act remain provisional for the transition tax, the remeasurement of deferred taxes, and the Company's reassessment of permanently reinvested earnings, uncertain tax positions and valuation allowances. These estimates may be impacted by further analysis and future clarification and guidance regarding available tax accounting methods and elections, earnings and profits computations, state tax conformity to federal tax changes and the impact of the GILTI provisions. The Company included an estimate of the GILTI impact for 2018 of $3.6 million in its tax provision. The Company's 2014 through 2017 tax periods remain open to examination by the Internal Revenue Service and the 2013 through 2017 tax periods remain open to examination by most state tax authorities. The Internal Revenue Service's examination of Inventus's federal income tax return for fiscal year 2013 was closed during the three months ended March 31, 2017 with no material adjustments. The Company's 2015 through 2017 tax periods remain open to examination in the United Kingdom.

Related-Party Transactions

3 Months Ended

Mar. 31, 2018

Related-Party Transactions

During the three months ended March 31, 2018 and 2017, two and four members, respectively, of the Company’s Board of Directors also served on the boards of directors of RPX clients.

The Company recognized the following from these clients (in millions):



	Three Months Ended March 31,
	2018		2017
Revenue	$	0.6	$	2.0
Selling, general and administrative expenses	$	0.1	$	0.2

As of March 31, 2018 and December 31, 2017, there were $3.0 million and $1.5 million receivables, respectively, from these clients.

Segment Reporting

3 Months Ended

Mar. 31, 2018

Segment Reporting [Abstract]

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 Officer reviews separate financial information for the patent risk management and discovery services businesses and therefore the Company has two reportable segments: 1) patent risk management which generates its revenues primarily from membership subscriptions, premiums earned from insurance policies, and management fees for marketing, underwriting, and claim management and 2) discovery services which generates its revenues primarily from fees generated for data collection, hosting and processing, project management, and document review services. There are no material internal revenue transactions between these two reportable segments.

Although adjusted EBITDA and adjusted operating income (loss) are not measures of financial performance determined in accordance with GAAP, the Company's chief operating decision maker evaluates segment financial performance by utilizing the segment's adjusted EBITDA and adjusted operating income (loss) because the Company believes it is a useful supplemental measure that reflects core operating performance and provides an indicator of the segment's ability to generate cash.

The Company defines adjusted EBITDA as net income exclusive of provision for income taxes, interest and other income (expense), net, impairment losses, stock-based compensation and related employer payroll taxes, depreciation, and amortization. The Company defines adjusted operating income (loss) as GAAP operating income (loss) exclusive of impairment losses. There are limitations in using the Company's measures of financial performance that are not determined in accordance with GAAP and these may be different from other financial measures not determined in accordance with GAAP used by other companies. These financial measures are limited in value because they exclude certain items that may have a material impact on the Company's reported financial results. In addition, they are subject to inherent limitations as they reflect the exercise of judgment by the Company about which items are adjusted to calculate its financial measures not determined in accordance with GAAP. The presentation of financial measures not determined in accordance with GAAP should not be considered in isolation or as a substitute for, or superior to, financial results determined in accordance with GAAP.

Summarized financial information by segment utilized by the Company's chief operating decision maker is as follows (in thousands):



	Three Months Ended March 31,
	2018			2017

Patent Risk Management
Revenue	$	46,742		$	57,389
Cost of revenue	30,634			34,272
Selling, general and administrative expenses	16,978			15,041
Adjusted operating income (loss)	(870		)	8,076
Stock-based compensation, including related taxes	3,358			2,441
Depreciation and amortization	30,022			33,310
Adjusted EBITDA	$	32,510		$	43,827

Discovery Services
Revenue	$	20,379		$	18,026
Cost of revenue	11,596			9,858
Selling, general and administrative expenses	7,274			6,687
Adjusted operating income	1,509			1,481
Stock-based compensation, including related taxes	510			434
Depreciation and amortization	2,571			2,421
Adjusted EBITDA	$	4,590		$	4,336

Consolidated
Revenue	$	67,121		$	75,415
Cost of revenue	42,230			44,130
Selling, general and administrative expenses	24,252			21,728
Adjusted operating income	$	639		$	9,557

The following table reconciles the Company's subtotal segment adjusted EBITDA to consolidated net income (in thousands):



	Three Months Ended March 31,
	2018			2017

Subtotal segment adjusted EBITDA	$	37,100		$	48,163
Depreciation and amortization	(32,593		)	(35,731		)
Stock-based compensation, including related taxes	(3,868		)	(2,875		)
Interest and other income (expense), net	862			(533		)
Provision for income taxes	(1,421		)	(3,369		)
Net income	$	80		$	5,655

The following table summarizes the Company's total assets by segment (in thousands):



	March 31, 2018		December 31, 2017
Patent risk management	$	398,285	$	399,362
Discovery services ⁽¹⁾	165,948		162,271
Total assets	$	564,233	$	561,633

⁽¹⁾Includes goodwill and intangible assets acquired through the Company's acquisition of Inventus in January 2016.

The following table sets forth the Company's revenue by type for each of the periods indicated, including revenue by segment (in thousands):



	Three Months Ended March 31,
	2018		2017
Subscription revenue	$	40,540	$	47,046
Fee-related revenue	6,202		10,343
Total patent risk management revenue	46,742		57,389
Discovery services revenue	20,379		18,026
Total revenue	$	67,121	$	75,415

The Company markets its solutions to companies around the world. Revenue is 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):



	Three Months Ended March 31,
	2018				2017
United States	$	40,333	60	%	$	42,704	57	%
Germany	6,764		10		6,968		9
Japan	8,151		12		10,060		13
Rest of world	11,873		18		15,683		21
Total revenue	$	67,121	100	%	$	75,415	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=68060357&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=68060357&loc=d3e9038-108599

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=68060357&loc=d3e8971-108599

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=68060357&loc=d3e8595-108599

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=68060357&loc=d3e8380-108599

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-URI http://asc.fasb.org/extlink&oid=68060357&loc=d3e8933-108599

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 26
-URI http://asc.fasb.org/extlink&oid=68060357&loc=d3e8844-108599

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 35
-URI http://asc.fasb.org/extlink&oid=68060357&loc=d3e8984-108599

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 40
-URI http://asc.fasb.org/extlink&oid=68060357&loc=d3e9031-108599

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI http://asc.fasb.org/extlink&oid=68060357&loc=d3e9054-108599

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
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Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
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-Paragraph 31
-URI http://asc.fasb.org/extlink&oid=68060357&loc=d3e8924-108599

Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-URI http://asc.fasb.org/extlink&oid=68060357&loc=d3e8906-108599

+ Details

Subsequent Events	3 Months Ended
Subsequent Events	Mar. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On April 30, 2018, the Company entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Riptide Parent, LLC, a Delaware limited liability company (“Parent”), and Riptide Purchaser, Inc., a Delaware corporation and a wholly owned subsidiary of Parent (“Purchaser”). Parent and Purchaser are beneficially owned by affiliates of HGGC, LLC (“HGGC”). Pursuant to the Merger Agreement, upon the terms and subject to the conditions thereof, Purchaser will commence a cash tender offer no later than May 21, 2018 to acquire all of the outstanding shares of common stock of the Company, $0.0001 par value per share (the “Company Common Stock”), at a price per share of Company Common Stock of $10.50 net to the seller in cash, without interest (such offer, as it may be amended from time to time in accordance with the Merger Agreement, the “Offer,” and such amount of consideration or any greater amount per share that may be paid pursuant to the Offer, the “Offer Price”), subject to any applicable withholding taxes. Parent intends to fund the Offer Price with a combination of committed debt and equity financing and the Company’s cash on hand. The transaction is not subject to a financing condition. The obligation of Purchaser to purchase Company Common Stock tendered in the Offer is subject to the satisfaction or waiver of a number of conditions set forth in the Merger Agreement, including but not limited to: (i) prior to the expiration of the Offer, there shall have been validly tendered and not validly withdrawn shares of Company Common Stock that, together with all other shares of Company Common Stock, if any, beneficially owned by Parent, Purchaser and their respective Affiliates (as defined in the Merger Agreement) and any shares of Company Common Stock that constitute “rollover stock” (as defined by Section 251(h)(6) of the Delaware General Corporation Law), represent at least one share of Company Common Stock more than 50% of the then outstanding shares of Company Common Stock calculated including shares underlying certain stock options, (ii) the expiration or termination of the waiting periods (and any extensions thereof) under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, (iii) approval being obtained or deemed to be obtained under the German Act of Restraints of Competition 1957, as amended (“GWB”), and (iv) each of the other conditions set forth in Exhibit A to the Merger Agreement. The Offer will initially expire at one minute after 11:59 p.m. (New York City time) on the date that is 20 business days following the commencement of the Offer. Under certain circumstances, Purchaser may be required or permitted to extend the Offer on one or more occasions in accordance with the terms set forth in the Merger Agreement and the applicable rules and regulations of the SEC. Purchaser will not be required to extend the Offer beyond October 30, 2018 (the “End Date”), and may not extend the Offer beyond the End Date without the prior written consent of the Company. As soon as practicable following Purchaser’s acceptance of Company Common Stock tendered pursuant to the Offer and upon the terms and subject to the conditions set forth in the Merger Agreement and in accordance with Section 251(h) of the Delaware General Corporation Law, Purchaser will merge with and into the Company, whereupon the separate existence of Purchaser shall cease and the Company shall be the surviving corporation (the “Merger”), without a meeting or vote of stockholders of the Company. At the effective time of the Merger (the “Effective Time”), the shares of Company Common Stock not purchased pursuant to the Offer (other than Company Common Stock owned by the Company as treasury stock, by Parent or Purchaser or by stockholders of the Company who have perfected their statutory rights of appraisal under Delaware General Corporate Law) will each be converted into the right to receive an amount equal to the Offer Price. The Merger Agreement includes representations, warranties and covenants of the parties customary for a transaction of this nature. Among other things, the Merger Agreement includes covenants by the parties to take all actions to secure required regulatory approvals, and from the date of the Merger Agreement until the Effective Time, the Company has agreed to conduct its business in the ordinary course of business and has agreed to certain other operating covenants, as set forth more fully in the Merger Agreement. The Company has also agreed not to solicit or initiate discussions with third parties regarding other acquisition proposals regarding the Company and has agreed to certain restrictions on its ability to respond to such proposals, provided that (x) the Company, subject to the terms and conditions of the Merger Agreement, may enter into negotiations or discussions concerning, or provide confidential information to persons making, certain unsolicited proposals if the Company’s Board of Directors determines in good faith such proposal constitutes or could reasonably be expected to lead to a Superior Company Proposal (as defined in the Merger Agreement), subject to certain rights of Parent pursuant to the terms of the Merger Agreement to negotiate with the Company, and (y) the Company’s Board of Directors may also change its recommendation regarding the Offer for a reason unrelated to an acquisition proposal in the context of a Company Intervening Event (as defined in the Merger Agreement), in either case, only if the Company’s Board of Directors determines that the failure to take such action would be inconsistent with its fiduciary duties. The Merger Agreement also contains certain termination provisions for the Company and Parent, including the right of the Company, in certain circumstances, to terminate the Merger Agreement and accept a Superior Company Proposal. The Company will be required to pay Parent a cash termination fee equal to $18,388,081 if, among other reasons, the Merger Agreement is terminated (i) by the Company to enter into an acquisition agreement that constitutes a Superior Company Proposal or (ii) by Parent because the Board of Directors of the Company adversely changes its recommendation to stockholders to accept the Offer and tender their shares of Company Common Stock to Purchaser in the Offer. Parent will be required to pay the Company a cash termination fee equal to $31,522,425 if, among other reasons, the Merger Agreement is terminated by the Company due to Parent or Purchaser’s (i) failure to accept and pay for shares of Company Common Stock validly tendered and not withdrawn in the Offer or (ii) failure to consummate the Merger. In addition, either the Company or Parent may terminate the Merger Agreement, at any time prior to the time Purchaser accepts for payment the Company Common Stock tendered pursuant to the Offer, if the Merger shall not have been consummated on or before the End Date. The Company expects the transaction to be consummated during the second or third quarter of 2018.

Basis of Presentation and Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2018

Accounting Policies [Abstract]

Basis of Presentation

Revenue Recognition

Patent Risk Management

Nature of Products and Services:


•	Subscription Revenue


•	Fee Revenue

•

Significant Judgments:

As part of the adoption of ASC 606, the Company elected to use the following practical expedients:


•	for completed contracts at transition that have variable consideration, the Company will use the transaction price at the date the contract was completed, rather than estimating variable consideration amounts in the comparative periods,


•	for contracts modified prior to January 1, 2016, the Company will reflect the aggregate effect of all modifications that occur before January 1, 2016 when identifying the satisfied and unsatisfied performance obligations, determining the transaction price and allocating the transaction price to the satisfied an unsatisfied performance obligations for the modified contract at transition, and


•	the Company will not adjust the promised amount of consideration for the effects of a significant financing component when the Company expects, at contract inception, that the period between the Company's transfer of a promised product or service to a customer and when the customer pays for that product or service will be one year or less.

Contract Balances:

The opening balance of current and long-term trade and non-trade unbilled receivables was $54.2 million as of January 1, 2016.

Recent Acc

Recent Accounting Pronouncements

Revenue from Contracts with Customers

The Company adopted the standard using the full retrospective method to recast each prior reporting period presented.

Revenue recognition related to the Company’s discovery services segment and its patent risk management insurance offering is not materially changed under ASC 606.

The Company recast its financial statements from amounts previously reported due to the adoption of ASC 606 shown below.



RPX Corporation
Consolidated Statements of Operations
Selected Line Items Under ASC 605 and ASC 606
(in thousands)
(unaudited)
	Three months ended March 31, 2017
	ASC 605		New Revenue Standard Adjustment			ASC 606
Revenue	$	82,512	$	(7,097	)	$	75,415
Cost of revenue	51,298		(7,168		)	44,130
Selling, general and administrative expenses	21,121		607			21,728
Provision for income taxes	3,567		(198		)	3,369
Net income	$	5,993	$	(338	)	$	5,655



RPX Corporation
Consolidated Balance Sheet
Selected Line Items Under ASC 605 and ASC 606
(in thousands)
(unaudited)
	December 31, 2017
	ASC 605		New Revenue Standard Adjustment			ASC 606
Accounts receivable, net	$	51,544	$	12,316		$	63,860
Prepaid expenses and other current assets	25,687		8,711			34,398
Patent assets, net	163,048		(31,160		)	131,888
Deferred tax assets	23,572		4,367			27,939
Other assets	3,664		16,569			20,233
Deferred revenue, current	105,150		(19,360		)	85,790
Deferred revenue, less current portion	1,718		(1,234		)	484
Retained earnings	$	39,411	$	31,397		$	70,808



RPX Corporation
Consolidated Statements of Cash Flows
Selected Line Items Under ASC 605 and ASC 606
(in thousands)
(unaudited)
	Three months ended March 31, 2017
	ASC 605			New Revenue Standard Adjustment			ASC 606
Operating activities
Net income	$	5,993		$	(338	)	$	5,655
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	42,929			(7,198		)	35,731
Deferred income taxes	2,109			(198		)	1,911
Other	(484		)	625			141
Changes in assets and liabilities:
Accounts receivable	27,815			4,118			31,933
Prepaid expenses and other assets	(5,572		)	(2,144		)	(7,716		)
Deferred revenue	5,819			1,177			6,996

Investing activities
Acquisitions of patent assets	$	(31,379	)	$	3,958		$	(27,421	)

In addition, the cumulative effect of ASC 606 to the Company’s retained earnings at January 1, 2016 was an increase of $44.8 million.

Basis of Presentation and Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2018

Accounting Policies [Abstract]

Schedule of New Accounting Pronouncements and Changes in Accounting Principles

The Company recast its financial statements from amounts previously reported due to the adoption of ASC 606 shown below.



RPX Corporation
Consolidated Statements of Operations
Selected Line Items Under ASC 605 and ASC 606
(in thousands)
(unaudited)
	Three months ended March 31, 2017
	ASC 605		New Revenue Standard Adjustment			ASC 606
Revenue	$	82,512	$	(7,097	)	$	75,415
Cost of revenue	51,298		(7,168		)	44,130
Selling, general and administrative expenses	21,121		607			21,728
Provision for income taxes	3,567		(198		)	3,369
Net income	$	5,993	$	(338	)	$	5,655



RPX Corporation
Consolidated Balance Sheet
Selected Line Items Under ASC 605 and ASC 606
(in thousands)
(unaudited)
	December 31, 2017
	ASC 605		New Revenue Standard Adjustment			ASC 606
Accounts receivable, net	$	51,544	$	12,316		$	63,860
Prepaid expenses and other current assets	25,687		8,711			34,398
Patent assets, net	163,048		(31,160		)	131,888
Deferred tax assets	23,572		4,367			27,939
Other assets	3,664		16,569			20,233
Deferred revenue, current	105,150		(19,360		)	85,790
Deferred revenue, less current portion	1,718		(1,234		)	484
Retained earnings	$	39,411	$	31,397		$	70,808

- Definition

Tabular disclosure of changes in accounting principles, including adoption of new accounting pronouncements, that describes the new methods, amount and effects on financial statement line items.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64853466&loc=d3e22580-107794

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Direct Effects of a Change in Accounting Principle
-URI http://asc.fasb.org/extlink&oid=66092750

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Indirect Effects of a Change in Accounting Principle
-URI http://asc.fasb.org/extlink&oid=6515603

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 270
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-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=68064558&loc=d3e765-108305

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Accounting Change
-URI http://asc.fasb.org/extlink&oid=6503790

Reference 6: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 250
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-Paragraph 1
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
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-Topic 270
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-Paragraph 1
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Reference 8: http://www.xbrl.org/2003/role/presentationRef
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-URI http://asc.fasb.org/extlink&oid=64853466&loc=d3e22583-107794

Reference 9: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Glossary Change in Accounting Principle
-URI http://asc.fasb.org/extlink&oid=6507316

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 270
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Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Retrospective Application
-URI http://asc.fasb.org/extlink&oid=6523989

+ Details

Net Income Per Share (Tables)

3 Months Ended

Mar. 31, 2018

Earnings Per Share [Abstract]

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 (in thousands, except per share data):



	Three Months Ended March 31,
	2018		2017
Numerator:
Net income	$	80	$	5,655
Denominator:
Basic shares:
Weighted-average shares used in computing basic net income per share	49,755		48,676
Diluted shares:
Weighted-average shares used in computing basic net income per share	49,755		48,676
Dilutive effect of stock options and restricted stock units using the treasury-stock method	512		629
Weighted-average shares used in computing diluted net income per share	50,267		49,305
Net income per share:
Basic	$	—	$	0.12
Diluted	$	—	$	0.11

Anti-Dilutive Securities Not Included In Diluted Shares Outstanding Calculation

The following securities were not included in the calculation of diluted shares outstanding as the effect would have been anti-dilutive (in thousands):



	Three Months Ended March 31,
	2018	2017
Outstanding weighted-average:
Stock options	582	718
Restricted stock units	562	765

Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Financial Assets Measured at Fair Value on a Recurring Basis

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



	March 31, 2018
	Amortized Cost		Unrealized					Estimated Fair Value		Level 1		Level 2
	Amortized Cost		Gains		Losses			Estimated Fair Value		Level 1		Level 2
Cash equivalents:
Commercial paper	$	16,230	$	—	$	—		$	16,230	$	—	$	16,230
Money market funds	57,969		—		—			57,969		57,969		—
Municipal bonds	2,251		—		—			2,251		—		2,251
U.S. government and agency securities	25,974		—		—			25,974		—		25,974
	$	102,424	$	—	$	—		$	102,424	$	57,969	$	44,455
Short-term investments:
Municipal bonds	$	9,032	$	—	$	(5	)	$	9,027	$	—	$	9,027



	December 31, 2017
	Amortized Cost		Unrealized					Estimated Fair Value		Level 1		Level 2
	Amortized Cost		Gains		Losses			Estimated Fair Value		Level 1		Level 2
Cash equivalents:
Commercial paper	$	13,035	$	—	$	—		$	13,035	$	—	$	13,035
Corporate bonds	1,205		—		—			1,205		—		1,205
Money market funds	52,267		—		—			52,267		52,267		—
Municipal bonds	13,060		—		—			13,060		—		13,060
U.S. government and agency securities	13,101		—		—			13,101		—		13,101
	$	92,668	$	—	$	—		$	92,668	$	52,267	$	40,401
Short-term investments:
Commercial paper	$	1,994	$	—	$	—		$	1,994	$	—	$	1,994
Corporate bonds	3,074		—		(3		)	3,071		—		3,071
Municipal bonds	11,888		—		(3		)	11,885		—		11,885
U.S. government and agency securities	1,508		—		(3		)	1,505		—		1,505
	$	18,464	$	—	$	(9	)	$	18,455	$	—	$	18,455

Financial Liabilities Measured at Fair Value on a Recurring Basis



	December 31, 2017
	Amortized Cost		Unrealized					Estimated Fair Value		Level 1		Level 2
	Amortized Cost		Gains		Losses			Estimated Fair Value		Level 1		Level 2
Cash equivalents:
Commercial paper	$	13,035	$	—	$	—		$	13,035	$	—	$	13,035
Corporate bonds	1,205		—		—			1,205		—		1,205
Money market funds	52,267		—		—			52,267		52,267		—
Municipal bonds	13,060		—		—			13,060		—		13,060
U.S. government and agency securities	13,101		—		—			13,101		—		13,101
	$	92,668	$	—	$	—		$	92,668	$	52,267	$	40,401
Short-term investments:
Commercial paper	$	1,994	$	—	$	—		$	1,994	$	—	$	1,994
Corporate bonds	3,074		—		(3		)	3,071		—		3,071
Municipal bonds	11,888		—		(3		)	11,885		—		11,885
U.S. government and agency securities	1,508		—		(3		)	1,505		—		1,505
	$	18,464	$	—	$	(9	)	$	18,455	$	—	$	18,455

Contract Balances (Tables)

3 Months Ended

Mar. 31, 2018

Revenue from Contract with Customer [Abstract]

Schedule of Unbilled Receivables and Deferred Revenue from Contracts with Customers

The Company's unbilled receivables and deferred revenue from contracts with customers consisted of the following (in thousands):



	March 31, 2018			December 31, 2017
Accounts receivable, net:
Unbilled trade receivables, current	$	10,192		$	12,316
Prepaid expenses and other current assets:
Unbilled non-trade receivables, current	8,021			8,711
Other assets:
Unbilled trade receivables, non-current	6,076			7,684
Unbilled non-trade receivables, non-current	8,923			8,884
Deferred revenue, current	(89,246		)	(85,790		)
Deferred revenue, non-current	(349		)	(484		)
Total deferred revenue, net	$	(56,383	)	$	(48,679	)

Schedule of Remaining Performance Obligations

The Company's unfulfilled performance obligations as of March 31, 2018 and the estimated revenue expected to be recognized in the future related to the performance obligations are as follows (in thousands):



2018 (remainder)	$	104,093
2019	72,415
2020	25,616
2021	2,209
2022	1,255
Thereafter	968
Total unfulfilled performance obligations	$	206,556

Patent Assets, Net (Tables)

3 Months Ended

Mar. 31, 2018

Patent Assets, Net [Abstract]

Patent Assets, Net

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



	December 31, 2017			Additions			Disposals			March 31, 2018
Patent assets	$	889,188		$	17,321		$	(8,232	)	$	898,277
Accumulated amortization	(757,300		)	(29,483		)	8,125			(778,658		)
Patent assets, net	$	131,888								$	119,619

Expected Future Annual Amortization Of Patent Assets

As of March 31, 2018, the Company expects amortization expense in future periods to be as follows (in thousands):



2018 (remainder)	$	65,297
2019	42,951
2020	11,282
2021	89
Total estimated future amortization expense	$	119,619

Property and Equipment, Net (Tables)

3 Months Ended

Mar. 31, 2018

Property, Plant and Equipment, Net, by Type [Abstract]

Property And Equipment, Net

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



	March 31, 2018			December 31, 2017
Internal-use software	$	8,729		$	8,530
Leasehold improvements	2,098			2,098
Computer, equipment and software	6,558			5,960
Furniture and fixtures	755			755
Construction-in-progress	25			21
Total property and equipment, gross	18,165			17,364
Less: Accumulated depreciation and amortization	(13,140		)	(12,274		)
Total property and equipment, net	$	5,025		$	5,090

Goodwill (Tables)

3 Months Ended

Mar. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill

The changes in the carrying amounts of goodwill by operating segment were as follows (in thousands):



	Patent Risk Management		Discovery Services		Total
Balance as of December 31, 2017	$	19,978	$	50,778	$	70,756
Foreign currency translation adjustments	—		1,755		1,755
Balance as of March 31, 2018	$	19,978	$	52,533	$	72,511

Intangible Assets, Net (Tables)

3 Months Ended

Mar. 31, 2018

Acquired Finite-Lived Intangible Assets [Line Items]

Intangible Assets, Net

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



	March 31, 2018							December 31, 2017
	Carrying Amount		Accumulated Amortization			Net Carrying Amount		Carrying Amount		Accumulated Amortization			Net Carrying Amount
Customer relationships	$	57,605	$	(13,553	)	$	44,052	$	56,688	$	(11,764	)	$	44,924
Trademarks	2,900		(1,058		)	1,842		2,900		(938		)	1,962
Developed technology	6,435		(4,613		)	1,822		6,237		(4,036		)	2,201
	$	66,940	$	(19,224	)	$	47,716	$	65,825	$	(16,738	)	$	49,087

Expected Future Annual Amortization Of Intangible Assets

As of March 31, 2018, the Company expects amortization expense in future periods to be as follows (in thousands):



2018 (remainder)	$	65,297
2019	42,951
2020	11,282
2021	89
Total estimated future amortization expense	$	119,619

Intangible Assets Net

Acquired Finite-Lived Intangible Assets [Line Items]

Expected Future Annual Amortization Of Intangible Assets

As of March 31, 2018, the Company expects amortization expense in future periods to be as follows (in thousands):



2018 (remainder)	$	6,540
2019	6,739
2020	6,615
2021	6,615
2022	6,160
Thereafter	15,047
Total estimated future amortization expense	$	47,716

Accrued Liabilities (Tables)

3 Months Ended

Mar. 31, 2018

Payables and Accruals [Abstract]

Accrued Liabilities

Accrued liabilities consisted of the following (in thousands):



	March 31, 2018		December 31, 2017
Accrued payroll-related expenses	$	6,090	$	10,669
Accrued other expenses	4,921		5,067
Total accrued liabilities	$	11,011	$	15,736

Commitments and Contingencies Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Non-cancelable operating leases

The following table summarizes rent expense related to non-cancelable operating leases (in millions):



	Three Months Ended March 31,
	2018			2017
Rent expense	$	1.4		$	1.6
Sublease income	(0.3		)	(0.3		)
Rent expense, net of sublease income	$	1.1		$	1.3

- Definition

Tabular disclosure of a lessee's leasing arrangements including: (1) the basis on which contingent rental payments are determined, (2) the existence and terms of renewal or purchase options and escalation clauses, (3) restrictions imposed by lease arrangements, such as those concerning dividends, additional debt, and further leasing, (4) rent holidays, rent concessions, or leasehold improvement incentives and unusual provisions or conditions. Disclosure may also include the specific period used to amortize material leasehold improvements made at the inception of the lease or during the lease term. Additionally, for operating leases having initial or remaining noncancelable lease terms in excess of one year: (a) future minimum rental payments required as of the date of the latest balance sheet presented, in the aggregate and for each of the five succeeding fiscal years, (b) the total of minimum rentals to be received in the future under noncancelable subleases as of the date of the latest balance sheet presented, and (c) for all operating leases, rental expense for each period for which an income statement is presented, with separate amounts for minimum rentals, contingent rentals, and sublease rentals. Rental payments under leases with terms of a month or less that were not renewed need not be included.

+ References + Details

Stockholders’ Equity (Tables)

3 Months Ended

Mar. 31, 2018

Stockholders Equity and Share-based Compensation [Abstract]

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, 2017	4,728		979		$	13.29
Options exercised	—		(39	)	3.61
Options forfeited/canceled	200		(200	)	14.91
Restricted stock units granted	(648	)	—		—
Restricted stock units forfeited	110		—		—
Restricted stock units withheld related to net-share settlement of restricted stock units	146		—		—
Balance - March 31, 2018	4,536		740		13.36		3.0	$	1,129
Vested and exercisable - March 31, 2018			740		13.36		3.0	1,129

Restricted Stock Unit Activity

The summary of RSU activity, which includes performance-based restricted stock units (“PBRSUs”), is as follows (in thousands, except per share data):



	Number of Shares		Weighted-Average Grant Date Fair Value		Aggregate Intrinsic Value
Non-vested units - December 31, 2017	2,520		$	11.95
Granted	648		13.43
Vested	(413	)	12.42
Forfeited	(110	)	11.93
Non-vested units - March 31, 2018	2,645		12.15		$	28,273

Schedule of Repurchase Agreements

The Company repurchased shares of its common stock in the open market, which were retired upon repurchase. The purchase price for the repurchased shares is reflected as a reduction to common stock and retained earnings in the Company's consolidated balance sheet. Share repurchase activity during the period presented was as follows (in thousands, except per share data):



	Shares Repurchased	Average Price per Share		Value of Shares Repurchased
Cumulative repurchase activity as of December 31, 2017	8,617	$	10.97	$	94,566
Repurchase activity during the period	—	—		—
Cumulative repurchase activity as of March 31, 2018	8,617	$	10.97	$	94,566

Dividends

Segment Reporting (Tables)

3 Months Ended

Mar. 31, 2018

Revenue from External Customer [Line Items]

Schedule of Segment Reporting Information, by Segment

The following table reconciles the Company's subtotal segment adjusted EBITDA to consolidated net income (in thousands):



	Three Months Ended March 31,
	2018			2017

Subtotal segment adjusted EBITDA	$	37,100		$	48,163
Depreciation and amortization	(32,593		)	(35,731		)
Stock-based compensation, including related taxes	(3,868		)	(2,875		)
Interest and other income (expense), net	862			(533		)
Provision for income taxes	(1,421		)	(3,369		)
Net income	$	80		$	5,655

The following table summarizes the Company's total assets by segment (in thousands):



	March 31, 2018		December 31, 2017
Patent risk management	$	398,285	$	399,362
Discovery services ⁽¹⁾	165,948		162,271
Total assets	$	564,233	$	561,633

⁽¹⁾Includes goodwill and intangible assets acquired through the Company's acquisition of Inventus in January 2016.

Summarized financial information by segment utilized by the Company's chief operating decision maker is as follows (in thousands):



	Three Months Ended March 31,
	2018			2017

Patent Risk Management
Revenue	$	46,742		$	57,389
Cost of revenue	30,634			34,272
Selling, general and administrative expenses	16,978			15,041
Adjusted operating income (loss)	(870		)	8,076
Stock-based compensation, including related taxes	3,358			2,441
Depreciation and amortization	30,022			33,310
Adjusted EBITDA	$	32,510		$	43,827

Discovery Services
Revenue	$	20,379		$	18,026
Cost of revenue	11,596			9,858
Selling, general and administrative expenses	7,274			6,687
Adjusted operating income	1,509			1,481
Stock-based compensation, including related taxes	510			434
Depreciation and amortization	2,571			2,421
Adjusted EBITDA	$	4,590		$	4,336

Consolidated
Revenue	$	67,121		$	75,415
Cost of revenue	42,230			44,130
Selling, general and administrative expenses	24,252			21,728
Adjusted operating income	$	639		$	9,557

The following table reconciles the Company's subtotal segment adjusted EBITDA to consolidated net income (in thousands):



	Three Months Ended March 31,
	2018			2017

Subtotal segment adjusted EBITDA	$	37,100		$	48,163
Depreciation and amortization	(32,593		)	(35,731		)
Stock-based compensation, including related taxes	(3,868		)	(2,875		)
Interest and other income (expense), net	862			(533		)
Provision for income taxes	(1,421		)	(3,369		)
Net income	$	80		$	5,655

Reconciliation of Revenue from Segments to Consolidated [Table Text Block]

The following table sets forth the Company's revenue by type for each of the periods indicated, including revenue by segment (in thousands):



	Three Months Ended March 31,
	2018		2017
Subscription revenue	$	40,540	$	47,046
Fee-related revenue	6,202		10,343
Total patent risk management revenue	46,742		57,389
Discovery services revenue	20,379		18,026
Total revenue	$	67,121	$	75,415

Revenue By Location

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):



	Three Months Ended March 31,
	2018				2017
United States	$	40,333	60	%	$	42,704	57	%
Germany	6,764		10		6,968		9
Japan	8,151		12		10,060		13
Rest of world	11,873		18		15,683		21
Total revenue	$	67,121	100	%	$	75,415	100	%

Basis of Presentation and Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Jan. 01, 2016
Accounting Policies [Abstract]
Revenue for calculation of annual subscription fees (as a percent)	5.00%
Average operating income calculation period for annual subscription fees	3 years
Unbilled receivables	$ 56,383		$ 48,679	$ 54,200
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cumulative effect recognized on initial application of the new guidance	68,390		70,808
Net cash provided by operating activities	33,167	$ 71,244
Net cash used in investing activities	8,787	5,783
Net cash used in financing activities	$ (4,289)	(7,131)
Difference between Revenue Guidance in Effect before and after Topic 606 \| Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cumulative effect recognized on initial application of the new guidance			$ 31,397	$ 44,800
Net cash used in investing activities		$ 4,000

Basis of Presentation and Significant Accounting Policies - Financial Statements due to Adoption of ASC 606 (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Jan. 01, 2016
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Depreciation and amortization expense	$ 32,593	$ 35,731
Consolidated Statements of Operations
Revenue	67,121	75,415
Cost of revenue	42,230	44,130
Selling, general and administrative expenses	24,252	21,728
Provision for income taxes	1,421	3,369
Net income	80	5,655
Consolidated Balance Sheet
Accounts receivable, net	77,485		$ 63,860
Prepaid expenses and other current assets	26,228		34,398
Patent assets, net	119,619		131,888
Deferred tax assets	27,257		27,939
Other assets	18,985		20,233
Deferred revenue, current	89,246		85,790
Deferred revenue, less current portion	349		484
Retained earnings	68,390		70,808
Deferred income taxes	580	1,911
Other Noncash Income (Expense)	81	141
Increase (Decrease) in Accounts Receivable	(13,126)	31,933
Increase (Decrease) in Prepaid Expense and Other Assets	9,543	(7,716)
Deferred revenue	3,320	6,996
Patent assets - Additions	$ (17,321)	(27,421)
Calculated under Revenue Guidance in Effect before Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Depreciation and amortization expense		42,929
Consolidated Statements of Operations
Revenue		82,512
Cost of revenue		51,298
Selling, general and administrative expenses		21,121
Provision for income taxes		3,567
Net income		5,993
Consolidated Balance Sheet
Accounts receivable, net			51,544
Prepaid expenses and other current assets			25,687
Patent assets, net			163,048
Deferred tax assets			23,572
Other assets			3,664
Deferred revenue, current			105,150
Deferred revenue, less current portion			1,718
Retained earnings			39,411
Deferred income taxes		2,109
Other Noncash Income (Expense)		(484)
Increase (Decrease) in Accounts Receivable		27,815
Increase (Decrease) in Prepaid Expense and Other Assets		(5,572)
Deferred revenue		5,819
Patent assets - Additions		(31,379)
Accounting Standards Update 2014-09 \| Difference between Revenue Guidance in Effect before and after Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Depreciation and amortization expense		(7,198)
Consolidated Statements of Operations
Revenue		(7,097)
Cost of revenue		(7,168)
Selling, general and administrative expenses		607
Provision for income taxes		(198)
Net income		(338)
Consolidated Balance Sheet
Accounts receivable, net			12,316
Prepaid expenses and other current assets			8,711
Patent assets, net			(31,160)
Deferred tax assets			4,367
Other assets			16,569
Deferred revenue, current			(19,360)
Deferred revenue, less current portion			(1,234)
Retained earnings			$ 31,397	$ 44,800
Deferred income taxes		(198)
Other Noncash Income (Expense)		625
Increase (Decrease) in Accounts Receivable		4,118
Increase (Decrease) in Prepaid Expense and Other Assets		(2,144)
Deferred revenue		1,177
Patent assets - Additions		$ 3,958

Net Income Per Share (Detail) - Basic and Diluted Net Income Per Share Available To Common Stockholders - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Numerator:
Net income	$ 80	$ 5,655
Basic shares:
Weighted-average shares used in computing basic net income per share	49,755	48,676
Diluted shares:
Dilutive effect of stock options and restricted stock units using the treasury-stock method	512	629
Weighted-average shares used in computing diluted net income per share	50,267	49,305
Net income per share:
Basic (dollars per common share)	$ 0.00	$ 0.12
Diluted (dollars per common share)	$ 0.00	$ 0.11

Net Income Per Share (Detail) - Anti-Dilutive Securities Not Included In Diluted Shares Outstanding Calculation - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Stock options
Outstanding weighted-average:
Weighted-average anti-dilutive securities	582	718
Restricted stock units
Outstanding weighted-average:
Weighted-average anti-dilutive securities	562	765

Financial Instruments (Detail) - Financial Assets Measured At Fair Value On A Recurring Basis - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 102,424	$ 92,668
Short-term investments, amortized cost		18,464
Short-term investments, unrealized gains		0
Short-term investments, unrealized losses		(9)
Short-term investments, total estimated fair value		18,455
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	57,969	52,267
Short-term investments, estimated fair value		0
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	44,455	40,401
Short-term investments, estimated fair value		18,455
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	16,230	13,035
Commercial paper \| Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Commercial paper \| Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	16,230	13,035
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		1,205
Corporate bonds \| Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		0
Corporate bonds \| Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		1,205
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	57,969	52,267
Money market funds \| Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	57,969	52,267
Money market funds \| Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	2,251	13,060
Municipal bonds \| Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Municipal bonds \| Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	2,251	13,060
U.S. government and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	25,974	13,101
U.S. government and agency securities \| Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
U.S. government and agency securities \| Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	25,974	13,101
Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, amortized cost	9,032	11,888
Short-term investments, unrealized gains	0	0
Short-term investments, unrealized losses	(5)	(3)
Short-term investments, total estimated fair value	9,027	11,885
Municipal bonds \| Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, estimated fair value	0	0
Municipal bonds \| Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, estimated fair value	$ 9,027	11,885
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, amortized cost		1,994
Short-term investments, unrealized gains		0
Short-term investments, unrealized losses		0
Short-term investments, total estimated fair value		1,994
Commercial paper \| Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, estimated fair value		0
Commercial paper \| Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, estimated fair value		1,994
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, amortized cost		3,074
Short-term investments, unrealized gains		0
Short-term investments, unrealized losses		(3)
Short-term investments, total estimated fair value		3,071
Corporate bonds \| Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, estimated fair value		0
Corporate bonds \| Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, estimated fair value		3,071
U.S. government and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, amortized cost		1,508
Short-term investments, unrealized gains		0
Short-term investments, unrealized losses		(3)
Short-term investments, total estimated fair value		1,505
U.S. government and agency securities \| Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, estimated fair value		0
U.S. government and agency securities \| Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, estimated fair value		$ 1,505

Financial Instruments (Detail)	3 Months Ended
Financial Instruments (Detail)	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Investment Holdings [Line Items]
Percentage of marketable securities investments maturing within one year	100.00%		100.00%
Percentage of marketable securities investments maturing within one to five years	0.00%		0.00%
Minimum
Investment Holdings [Line Items]
Maturity term within one year (in years)	1 year	1 year
Maturity term within one to five years (in years)	1 year	1 year
Maximum
Investment Holdings [Line Items]
Maturity term within one to five years (in years)	5 years	5 years

Contract Balances - Unbilled Receivables and Deferred Revenue (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Jan. 01, 2016
Accounts receivable, net:
Unbilled trade receivables, current	$ 10,192	$ 12,316
Prepaid expenses and other current assets:
Unbilled non-trade receivables, current	8,021	8,711
Other assets:
Unbilled trade receivables, non-current	6,076	7,684
Unbilled non-trade receivables, non-current	8,923	8,884
Deferred revenue, current	(89,246)	(85,790)
Deferred revenue, non-current	(349)	(484)
Total deferred revenue, net	$ (56,383)	$ (48,679)	$ (54,200)

Contract Balances - Performance Obligations (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
2018-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 104,093
Performance obligations expected to be satisfied, expected timing	9 months
2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 72,415
Performance obligations expected to be satisfied, expected timing	1 year
2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 25,616
Performance obligations expected to be satisfied, expected timing	1 year
2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 2,209
Performance obligations expected to be satisfied, expected timing	1 year
2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 1,255
Performance obligations expected to be satisfied, expected timing	1 year
2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 968
Performance obligations expected to be satisfied, expected timing
Nil
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 206,556

Patent Assets, Net (Detail) - USD ($) $ in Thousands	3 Months Ended
Patent Assets, Net (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Mar. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization - Additions	$ 2,200	$ 2,300
Patents
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization - Additions	29,483
Amortization expense	$ 29,600	$ 32,600
Remaining weighted average amortization period	25 months
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

Patent Assets, Net (Detail) - Patent Assets, Net - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Finite-lived Intangible Assets [Roll Forward]
Patent assets, beginning balance	$ 65,825
Patent assets - Additions	17,321	$ 27,421
Patent assets, ending balance	66,940
Accumulated amortization, beginning balance	(16,738)
Accumulated amortization - Additions	(2,200)	(2,300)
Accumulated amortization, ending balance	(19,224)
Patent assets, net	119,619		$ 131,888
Patents
Finite-Lived Intangible Assets [Line Items]
Amortization expense	29,600	$ 32,600
Finite-lived Intangible Assets [Roll Forward]
Patent assets, beginning balance	889,188
Patent assets - Additions	17,321
Patent assets - Sales	(8,232)
Patent assets, ending balance	898,277
Accumulated amortization, beginning balance	(757,300)
Accumulated amortization - Additions	(29,483)
Accumulated amortization - Sales	8,125
Accumulated amortization, ending balance	(778,658)
Patent assets, net	$ 119,619		$ 131,888
Minimum \| Patents
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, useful life	24 months
Maximum \| Patents
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, useful life	60 months
Weighted Average \| Patents
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, useful life	38 months

Patent Assets, Net (Detail) - Expected Future Annual Amortization Expense Of Patent Assets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
2018 (remainder)	$ 6,540
2018	6,739
2019	6,615
2020	6,615
Patent assets, net	119,619	$ 131,888
Patents
Finite-Lived Intangible Assets [Line Items]
2018 (remainder)	65,297
2018	42,951
2019	11,282
2020	89
Patent assets, net	$ 119,619	$ 131,888

Property and Equipment, Net (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense	$ 32,593	$ 35,731
Property and equipment, types
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense	$ 800	$ 800

Property and Equipment, Net (Detail) - Property And Equipment, Net - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 18,165	$ 17,364
Less: Accumulated depreciation and amortization	(13,140)	(12,274)
Total property and equipment, net	5,025	5,090
Internal-use software
Property, Plant and Equipment [Line Items]
Internal-use software	8,729	8,530
Leasehold improvements
Property, Plant and Equipment [Line Items]
Leasehold improvements	2,098	2,098
Computer, equipment and software
Property, Plant and Equipment [Line Items]
Computer, equipment and software	6,558	5,960
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Furniture and fixtures	755	755
Construction-in-progress
Property, Plant and Equipment [Line Items]
Construction-in-progress	$ 25	$ 21

Goodwill (Details) $ in Thousands	3 Months Ended
Goodwill (Details) $ in Thousands	Mar. 31, 2018 USD ($)
Goodwill [Roll Forward]
Goodwill	$ 70,756
Foreign currency translation adjustments	1,755
Goodwill	72,511
Patent Risk Management
Goodwill [Roll Forward]
Goodwill	19,978
Foreign currency translation adjustments	0
Goodwill	19,978
Discovery Services
Goodwill [Roll Forward]
Goodwill	50,778
Foreign currency translation adjustments	1,755
Goodwill	$ 52,533

Intangible Assets, Net (Detail) - USD ($) $ in Millions	3 Months Ended
Intangible Assets, Net (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Mar. 31, 2017
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Amortization of intangible assets	$ 2.2	$ 2.3

Intangible Assets, Net (Detail) - Intangible Assets, Net - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	$ 66,940		$ 65,825
Accumulated amortization	(19,224)		(16,738)
Total estimated future amortization expense	47,716		49,087
Amortization of intangible assets	2,200	$ 2,300
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	57,605		56,688
Accumulated amortization	(13,553)		(11,764)
Total estimated future amortization expense	44,052		44,924
Trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	2,900		2,900
Accumulated amortization	(1,058)		(938)
Total estimated future amortization expense	1,842		1,962
Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	6,435		6,237
Accumulated amortization	(4,613)		(4,036)
Total estimated future amortization expense	$ 1,822		$ 2,201

Intangible Assets, Net (Detail) - Estimated Future Amortization Expenses For Intangible Assets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Intangible Assets, Net (Excluding Goodwill) [Abstract]
2018 (remainder)	$ 6,540
2018	6,739
2019	6,615
2020	6,615
2021	6,160
Thereafter	15,047
Total estimated future amortization expense	$ 47,716	$ 49,087

Accrued Liabilities (Detail) - Accrued Liabilities - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Accrued liabilities	$ 11,011	$ 15,736
Accrued payroll-related expenses
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Accrued liabilities	6,090	10,669
Accrued other expenses
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Accrued liabilities	$ 4,921	$ 5,067

Commitments and Contingencies (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Contractual obligation term	3 years
Reserves for known and incurred but not reported claims	$ 0.9	$ 1.1

Commitments and Contingencies - Summary of Noncancelable Operating Leases (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 1.4	$ 1.6
Sublease income	(0.3)	(0.3)
Rent expense, net of sublease income	$ 1.1	$ 1.3

Stockholders’ Equity (Detail) - USD ($)	3 Months Ended
Stockholders’ Equity (Detail) - USD ($)	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of stock options exercised	$ 300,000	$ 700,000
Total fair value of stock options vested	0
Total fair value of RSUs vested	$ 5,400,000	4,400,000
Shares withheld for tax withholdings (in shares)	146,002
Total payments for the employees’ minimum tax obligations to taxing authorities	$ 1,895,000	1,708,000
PBRSUs and RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3,600,000	$ 2,700,000
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested equity awards	$ 29,100,000
Weighted-average service period of unrecognized compensation cost related to unvested equity awards	2 years 9 months

Stockholders’ Equity (Detail) - Activity Under Equity Award Plans And Related Information $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Available for Grant - Outstanding, beginning balance (in shares)	4,728,000
Number of Shares - Outstanding, beginning balance (in shares)	979,000
Options forfeited/canceled (in shares)	(200,000)
Shares Available for Grant - Options forfeited/canceled (in shares)	200,000
Number of Shares - Options exercised (in shares)	(39,000)
Share Available for Grant - Restricted stock units granted (in shares)	(648,000)
Shares Available for Grant - Restricted stock units forfeited (in shares)	110,000
Shares Available for Grant - Outstanding, ending balance (in shares)	4,536,000
Number of Shares - Outstanding, ending balance (in shares)	740,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted-Average Exercise Price - Outstanding, beginning balance (in dollars per share) \| $ / shares	$ 13.29
Weighted Average Exercise Price - Options exercised (in dollars per share) \| $ / shares	$ 3.61
Shares Available for Grant - Restricted stock units withheld related to net-share settlement of restricted stock units (in shares)	146,000
Weighted Average Exercise Price - Options forfeited/canceled (in dollars per share) \| $ / shares	$ 14.91
Weighted-Average Exercise Price - Outstanding, ending balance (in dollars per share) \| $ / shares	$ 13.36
Outstanding (weighted-average contractual life)	3 years
Outstanding (intrinsic value) \| $	$ 1,129
Vested and exercisable
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Vested and exercisable (shares)	740,000
Vested and exercisable (in dollars per share) \| $ / shares	$ 13.36
Vested and exercisable (weighted-average contractual life)	3 years
Vested and exercisable (intrinsic value) \| $	$ 1,129

Stockholders’ Equity (Detail) - Restricted Stock Unit Activity - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Non-vested units, beginning balance (in shares)	2,520,000
Non-vested units, ending balance (in shares)	2,645,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Non-vested units, beginning balance (in dollars per share)	$ 11.95
Non-vested units, ending balance (in dollars per share)	$ 12.15
Share-based compensation arrangement by share-based payment award, equity instruments other than options, nonvested, intrinsic value	$ 28,273
PBRSUs and RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 3,600	$ 2,700
Restricted stock units granted
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted (in shares)	648,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Granted (in dollars per share)	$ 13.43
Restricted stock units vested
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Vested (in shares)	(413,000)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Vested (in dollars per share)	$ 12.42
Restricted stock units forfeited
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Forfeited (in shares)	(110,000)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Forfeited (in dollars per share)	$ 11.93

Stockholders’ Equity (Detail) - Repurchased and Retired Common Stock - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	May 31, 2016
Stockholders Equity and Share-based Compensation [Abstract]
Share repurchase program, authorized amount	$ 150,000	$ 75,000
Increase in authorized amount			$ 25,000	$ 50,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares repurchased, balance as of beginning of period (in shares)	8,617
Shares repurchased, repurchase of shares of common stock (in shares)	0
Shares repurchased, balance as of end of period (in shares)	8,617
Shares repurchased, average price per share at beginning of period (usd per share)	$ 10.97
Shares repurchased, average price per share for repurchase of shares of common stock (usd per share)	0.00
Shares repurchased, average price per share at end of period (usd per share)	$ 10.97
Shares repurchased, value of shares repurchased as of beginning of period	$ 94,566
Shares repurchased, value of repurchase of shares of common stock	0
Shares repurchased, value of shares repurchased as of end of period	$ 94,566

Income Taxes Income Taxes (Details)	3 Months Ended
Income Taxes Income Taxes (Details)	Mar. 31, 2018	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Effective tax rate	95.00%	37.00%

Related-Party Transactions (Detail) $ in Millions	3 Months Ended
Related-Party Transactions (Detail) $ in Millions	Mar. 31, 2018 USD ($) board_member	Mar. 31, 2017 USD ($) board_member	Dec. 31, 2017 USD ($)
Related Party Transaction [Line Items]
Revenue from related parties	$ 0.6	$ 2.0
Selling, general, and administrative expenses from products and services provided by clients	0.1	$ 0.2
Receivables due from related parties	$ 3.0		$ 1.5
Director
Related Party Transaction [Line Items]
Number of directors \| board_member	2	4

Segment Reporting (Detail) $ in Thousands	3 Months Ended
Segment Reporting (Detail) $ in Thousands	Mar. 31, 2018 USD ($) segment	Mar. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Revenue	$ 67,121	$ 75,415
Cost of revenue	42,230	44,130
Selling, general and administrative expenses	24,252	21,728
Adjusted Operating Income (Loss)	639	9,557
Adjusted operating income (loss)	639	9,557
Depreciation and amortization	32,593	35,731
Adjusted EBITDA	$ 37,100	48,163
Number of reportable segments \| segment	2
Operating Segments [Member] \| Legacy RPX
Segment Reporting Information [Line Items]
Revenue	$ 46,742	57,389
Cost of revenue	30,634	34,272
Selling, general and administrative expenses	16,978	15,041
Adjusted Operating Income (Loss)	(870)	8,076
Stock-based compensation, including related taxes	3,358	2,441
Depreciation and amortization	30,022	33,310
Adjusted EBITDA	32,510	43,827
Operating Segments [Member] \| Discovery Services
Segment Reporting Information [Line Items]
Revenue	20,379	18,026
Cost of revenue	11,596	9,858
Selling, general and administrative expenses	7,274
Adjusted Operating Income (Loss)	1,509	1,481
Stock-based compensation, including related taxes	510	434
Depreciation and amortization	2,571	2,421
Adjusted EBITDA	4,590	4,336
Subscription revenue \| Operating Segments [Member] \| Legacy RPX
Segment Reporting Information [Line Items]
Revenue	40,540	47,046
Fee-related revenue \| Operating Segments [Member] \| Legacy RPX
Segment Reporting Information [Line Items]
Revenue	$ 6,202	$ 10,343

Segment Reporting (Detail) - Revenue By Location - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Total revenue	$ 67,121	$ 75,415
Total revenue	100.00%	100.00%
United States
Segment Reporting Information [Line Items]
United States	60.00%	57.00%
Total revenue	$ 40,333	$ 42,704
Germany
Segment Reporting Information [Line Items]
United States	10.00%	9.00%
Total revenue	$ 6,764	$ 6,968
Japan
Segment Reporting Information [Line Items]
Other foreign country	12.00%	13.00%
Total revenue	$ 8,151	$ 10,060
Rest of world
Segment Reporting Information [Line Items]
Other foreign country	18.00%	21.00%
Total revenue	$ 11,873	$ 15,683

Segment Reporting - Subtotal Segment Adjusted EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting [Abstract]
Adjusted EBITDA	$ 37,100	$ 48,163
Depreciation and amortization	(32,593)	(35,731)
Stock-based compensation, including related taxes	(3,868)	(2,875)
Interest and other income (expense), net	862	(533)
Provision for income taxes	(1,421)	(3,369)
Net income	80	5,655
Revenue	67,121	75,415
Cost of revenue	42,230	44,130
Selling, general and administrative expenses	$ 24,252	$ 21,728

Segment Reporting - Total Assets by Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Assets	$ 564,233	$ 561,633
Operating Segments [Member] \| Patent risk management
Segment Reporting Information [Line Items]
Assets	398,285	399,362
Operating Segments [Member] \| Discovery Services
Segment Reporting Information [Line Items]
Assets	$ 165,948	$ 162,271

Subsequent Events - Narrative (Details) - USD ($)	Apr. 30, 2018	Mar. 31, 2018
Subsequent Event [Line Items]
Common stock par value (USD per share)		$ 0.0001
RPX Corporation \| Riptide Parent, LLC \| Subsequent Event
Subsequent Event [Line Items]
Acquisition price per share (USD per share)	$ 10.50
Fee for termination by company	$ 18,388,081
Fee for termination by parent	$ 31,522,425