Rambus (RMBS) 10-Q 28 Jul 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	6 Months Ended
	Jun. 30, 2017shares
Document and Entity Information
Entity Registrant Name	RAMBUS INC
Entity Central Index Key	917,273
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Current Reporting Status	Yes
Entity Common Stock, Shares Outstanding	109,277,223

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 167,207	$ 135,294
Marketable securities	746	36,888
Accounts receivable	36,788	21,099
Inventories	5,328	5,633
Prepaids and other current assets	12,255	17,867
Total current assets	222,324	216,781
Intangible Assets, Net	111,875	132,388
Goodwill	207,959	204,794
Property, plant and equipment, net	54,305	58,442
Deferred tax assets	204,267	168,342
Other assets	2,564	2,749
Total assets	803,294	783,496
Current liabilities:
Accounts payable	9,099	9,793
Accrued salaries and benefits	14,076	14,177
Deferred revenue	21,327	16,932
Other current liabilities	6,615	10,399
Total current liabilities	51,117	51,301
Convertible notes, long-term	129,690	126,167
Long-term imputed financing obligation	37,677	38,029
Other long-term liabilities	14,592	15,217
Total liabilities	233,076	230,714
Commitments and contingencies (Notes 9 and 13)
Stockholders’ equity:
Convertible preferred stock, $.001 par value: Authorized: 5,000,000 shares Issued and outstanding: no shares at June 30, 2017 and December 31, 2016	0	0
Common stock, $.001 par value: Authorized: 500,000,000 shares Issued and outstanding: 109,277,223 shares at June 30, 2017 and 111,053,734 shares at December 31, 2016	109	111
Additional paid-in capital	1,179,283	1,181,230
Accumulated deficit	(600,557)	(615,051)
Accumulated other comprehensive loss	(8,617)	(13,508)
Total stockholders’ equity	570,218	552,782
Total liabilities and stockholders’ equity	$ 803,294	$ 783,496

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Jun. 30, 2017	Dec. 31, 2016
Stockholders’ equity:
Convertible preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Convertible preferred stock, Authorized shares	5,000,000	5,000,000
Convertible preferred stock, Issued shares	0	0
Convertible preferred stock, Outstanding shares	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, Authorized shares	500,000,000	500,000,000
Common stock, Issued shares	109,277,223	111,053,734
Common stock, Outstanding shares	109,277,223	111,053,734

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenue:
Royalties		$ 69,990	$ 62,835	$ 138,946	$ 125,712
Product revenue		8,401	3,902	19,305	7,214
Contract and other revenue		16,329	9,764	33,820	16,257
Total revenue		94,720	76,501	192,071	149,183
Operating costs and expenses:
Cost of product revenue	[1]	7,480	3,016	12,730	5,550
Cost of contract and other revenue		14,337	11,073	28,818	20,746
Research and development	[1]	37,522	28,753	73,522	57,280
Sales, general and administrative	[1]	27,137	21,789	55,323	44,884
Gain from settlement		0	(138)	0	(579)
Total operating costs and expenses		86,476	64,493	170,393	127,881
Operating income (loss)		8,244	12,008	21,678	21,302
Interest income and other income (expense), net		129	1,138	283	1,380
Interest expense		(3,261)	(3,163)	(6,467)	(6,304)
Interest and other income (expense), net		(3,132)	(2,025)	(6,184)	(4,924)
Income before income taxes		5,112	9,983	15,494	16,378
Provision for (benefit from) income taxes		2,507	6,107	9,883	10,624
Net Income (Loss)		$ 2,605	$ 3,876	$ 5,611	$ 5,754
Net income per share:
Earnings Per Share, Basic		$ 0.02	$ 0.04	$ 0.05	$ 0.05
Earnings Per Share, Diluted		$ 0.02	$ 0.03	$ 0.05	$ 0.05
Weighted average shares used in per share calculation:
Basic (in shares)		110,060	109,904	110,758	109,818
Diluted (in shares)		112,565	112,061	114,091	112,202
[1]	Includes stock-based compensation

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Cost of product revenue
Stock-based compensation	$ 19	$ 14	$ 33	$ 28
Research and development
Stock-based compensation	3,067	2,109	6,079	4,189
Sales, general and administrative
Stock-based compensation	$ 3,523	$ 2,926	$ 7,093	$ 5,696

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$ 2,605	$ 3,876	$ 5,611	$ 5,754
Other comprehensive income (loss):
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	3,597	(5,559)	4,596	(6,199)
Unrealized gain (loss) on marketable securities, net of tax	55	(188)	295	(371)
Total comprehensive income (loss)	$ 6,257	$ (1,871)	$ 10,502	$ (816)

CONDENSED CONSOLIDATED STATEME7

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net Income (Loss)	$ 5,611	$ 5,754
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation	13,205	9,913
Depreciation	6,722	5,965
Amortization of intangible assets	20,938	15,871
Non-cash interest expense and amortization of convertible debt issuance costs	3,523	3,326
Excess tax benefits from stock-based compensation, Operating Activities	0	(591)
Deferred income taxes	514	2,816
(Gain) loss from disposal of property, plant and equipment	180	(37)
Effect of Exchange Rate on assumed cash liability from acquisition	0	624
Change in operating assets and liabilities, net of impact of acquisitions:
Accounts receivable	(13,152)	14,809
Prepaid expenses and other assets	5,116	(1,319)
Inventories	304	(537)
Accounts payable	(396)	2,167
Accrued salaries and benefits and other liabilities	(4,122)	(9,046)
Deferred revenue	4,090	1,794
Net cash provided by operating activities	42,533	50,261
Cash flows from investing activities:
Purchases of property, plant and equipment	(3,482)	(3,557)
Purchases of marketable securities	0	54,869
Maturities of marketable securities	32,048	81,971
Proceeds from sale of marketable securities	4,450	44,546
Proceeds from sale of property, plant, and equipment	17	0
Acquisitions of businesses, net of cash acquired	0	(80,523)
Net cash provided by (used in) investing activities	33,033	(12,432)
Cash flows from financing activities:
Excess tax benefits from stock-based compensation, Financing Activities	0	591
Proceeds received from issuance of common stock under employee stock plans	8,345	8,259
Principal payments against lease financing obligation	(395)	(295)
Payments Related to Tax Withholding for Share-based Compensation	(2,824)	(1,572)
Payments for Repurchase of Common Stock	(50,036)	0
Net cash provided by (used in) financing activities	(44,910)	6,983
Effect of Exchange Rate on Cash and Cash Equivalents	1,257	(565)
Net increase in cash and cash equivalents	31,913	44,247
Cash and cash equivalents at beginning of period	135,294	143,764
Cash and cash equivalents at end of period	167,207	188,011
Non-cash investing and financing activities during the period:
Assumed cash liability from acquisition	0	11,476
Property, plant and equipment received and accrued in accounts payable and other liabilities	$ 176	$ 246

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the accounts of Rambus Inc. (“Rambus” or the “Company”) and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in the accompanying unaudited condensed consolidated financial statements. In the opinion of management, the unaudited condensed consolidated financial statements include all adjustments (consisting only of normal recurring items) necessary to state fairly the financial position and results of operations for each interim period presented. Interim results are not necessarily indicative of results for a full year. The unaudited condensed consolidated financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”) applicable to interim financial information. Certain information and Note disclosures included in the financial statements prepared in accordance with generally accepted accounting principles have been omitted in these interim statements pursuant to such SEC rules and regulations. The information included in this Form 10-Q should be read in conjunction with the consolidated financial statements and notes thereto in Form 10-K for the year ended December 31, 2016 . Operating Segment Definitions Operating segments are based upon Rambus' internal organization structure, the manner in which its operations are managed, the criteria used by its Chief Operating Decision Maker ("CODM") to evaluate segment performance and availability of separate financial information regularly reviewed for resource allocation and performance assessment. The Company determined its CODM to be the Chief Executive Officer and determined its operating segments to be: (1) Memory and Interfaces Division ("MID"), which focuses on the design, development, manufacturing through partnerships and licensing of technology and solutions that is related to memory and interfaces; (2) Rambus Security Division ("RSD"), which focuses on the design, development, deployment and licensing of technologies for chip, system and in-field application security, anti-counterfeiting, smart ticketing and mobile payments; (3) Emerging Solutions Division ("ESD"), which includes the Rambus Labs team, the computational sensing and imaging group as well as the development efforts in the area of emerging technologies; and (4) Rambus Lighting Division ("RLD"), which focuses on the design, development and licensing of technologies for advanced LED-based lighting solutions. For the three and six months ended June 30, 2017 , only MID and RSD were reportable segments as each of them met the quantitative thresholds for disclosure as a reportable segment. The results of the remaining other operating segments were shown under “Other.” Reclassifications Certain prior periods' amounts were reclassified to conform to the current year’s presentation. None of these reclassifications had an impact on reported net income for any of the periods presented. Product revenue and related cost of product revenue were reclassified from contract and other revenue and cost of contract and other revenue, respectively. Refer to the Unaudited Condensed Consolidated Statements of Operations.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Jun. 30, 2017
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements In July 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2017-11, "Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), Derivatives and Hedging (Topic 815)." The amendments in Part I of this ASU change the classification analysis of certain equity-linked financial instruments (or embedded features) with down round features. When determining whether certain financial instruments should be classified as liabilities or equity instruments, a down round feature no longer precludes equity classification when assessing whether the instrument is indexed to an entity’s own stock. The amendments also clarify existing disclosure requirements for equity-classified instruments. As a result, a freestanding equity-linked financial instrument (or embedded conversion option) no longer would be accounted for as a derivative liability at fair value as a result of the existence of a down round feature. For freestanding equity classified financial instruments, the amendments require entities that present earnings per share (EPS) in accordance with Topic 260 to recognize the effect of the down round feature when it is triggered. That effect is treated as a dividend and as a reduction of income available to common shareholders in basic EPS. Convertible instruments with embedded conversion options that have down round features are now subject to the specialized guidance for contingent beneficial conversion features (in Subtopic 470-20, Debt-Debt with Conversion and Other Options), including related EPS guidance (in Topic 260). The amendments in Part II of this ASU recharacterize the indefinite deferral of certain provisions of Topic 480 that now are presented as pending content in the FASB codification, to a scope exception. Those amendments do not have an accounting effect. This ASU is effective for interim and annual reporting periods beginning after December 15, 2018. Early adoption is permitted, including adoption in an interim period. The Company is currently evaluating the impact that this guidance will have on its consolidated financial statements. In May 2017, the FASB issued ASU No. 2017-09, "Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting," which amends the scope of modification accounting for share-based payment arrangements. Specifically, an entity would not apply modification accounting if the fair value, vesting conditions, and classification of the awards are the same immediately before and after the modification. This ASU is effective for interim and annual reporting periods beginning after December 15, 2017. Early adoption is permitted, including adoption in an interim period. The Company is currently evaluating the impact that this guidance will have on its consolidated financial statements. In March 2017, the FASB issued ASU No. 2017-08, "Receivables - Nonrefundable Fees and Other Costs (Topic 310): Premium Amortization on Purchased Callable Debt Securities," which amends the amortization period for certain purchased callable debt securities held at a premium. This ASU will shorten the amortization period for the premium to be amortized to the earliest call date. This ASU does not apply to securities held at a discount, which will continue to be amortized to maturity. This ASU is effective for interim and annual reporting periods beginning after December 15, 2018. Early adoption is permitted, including adoption in an interim period. The Company is currently evaluating the impact that this guidance will have on its consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, "Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment," which removes Step 2 of the goodwill impairment test. A goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. This ASU is effective for interim and annual reporting periods beginning after December 15, 2019. Early adoption is permitted, including adoption in an interim period. The Company is currently evaluating the impact that this guidance will have on its consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, "Business Combinations (Topic 805): Clarifying the Definition of a Business." The amendment seeks to clarify the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill and consolidation. This ASU is effective for interim and annual reporting periods beginning after December 15, 2017, including interim periods within those periods. The amendments should be applied prospectively on or after the effective dates. The Company is currently evaluating the impact that this guidance will have on its consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15 which amends the guidance on the classification of certain cash receipts and payments in the statement of cash flows. This ASU is effective for annual and interim reporting periods beginning after December 15, 2017 and is applied retrospectively. Early adoption is permitted including adoption in an interim period. The Company is currently evaluating the impact that this guidance will have on its financial condition and results of operations. In June 2016, the FASB issued ASU No. 2016-13. The purpose of this ASU is to require a financial asset measured at amortized cost basis to be presented at the net amount expected to be collected. Credit losses relating to available-for-sale debt securities should be recorded through an allowance for credit losses. This ASU is effective for interim and annual reporting periods beginning after December 15, 2019. The Company is currently evaluating the impact that this guidance will have on its financial condition and results of operations. In March 2016, the FASB issued ASU No. 2016-09, "Improvements to Employee Share-Based Payment Accounting." This ASU simplifies the accounting for share-based payment transactions including the accounting for income taxes, forfeitures, statutory tax withholding requirements and classification in the statement of cash flows. The updated standard no longer requires cash flows related to excess tax benefits to be presented as a financing activity separate from other income tax cash flows. The update also allows entities to repurchase more of an employee's shares for tax withholding purposes without triggering liability accounting, clarifies that all cash payments to taxing authorities made on an employee's behalf for withheld shares should be presented as a financing activity on the statement of cash flows, and provides for an accounting policy election to account for forfeitures as they occur. The Company adopted this ASU on January 1, 2017. The impact of the adoption is as follows: • This ASU requires excess tax benefits to be recognized regardless of whether the benefit reduces taxes payable. The adoption of this guidance on a modified retrospective basis resulted in the recognition of a cumulative-effect adjustment of $38.2 million that reduced the Company's accumulated deficit and increased its deferred tax assets as of January 1, 2017. The previously unrecognized California excess tax effects were recorded as a deferred tax asset net of a valuation allowance. • The Company has elected to continue to estimate forfeitures expected to occur to determine the amount of stock-based compensation cost to be recognized in each period. As such, the guidance relating to forfeitures did not have an impact on its accumulated deficit as of January 1, 2017. • Additionally, the Company anticipates the potential for increased periodic volatility in future effective tax rates as a result of the continued application of ASU No. 2016-09. In February 2016, the FASB issued ASU No. 2016-02, "Leases." This ASU requires lessees to recognize right-of-use assets and liabilities for operating leases, initially measured at the present value of the lease payments, on the balance sheet. In addition, it requires lessees to recognize a single lease cost, calculated so that the cost of the lease is allocated over the lease term, generally on a straight-line basis. This ASU will become effective for the Company in the first quarter of fiscal year 2019, and requires adoption using a modified retrospective approach. The Company is evaluating the impact of adopting this new accounting standard update on its consolidated financial statements and related disclosures and anticipates this new guidance will materially impact the Company’s financial statements given the Company has a significant number of operating leases. In July 2015, the FASB issued ASU No. 2015-11, "Simplifying the Measurement of Inventory (Topic 330)," which applies to inventory that is measured using first-in, first-out (“FIFO”) or average cost. Under the updated guidance, an entity should measure inventory that is within scope at the lower of cost and net realizable value, which is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. Subsequent measurement is unchanged for inventory that is measured using last-in, last-out (“LIFO”). This ASU is effective for annual and interim periods beginning after December 15, 2016, and should be applied prospectively with early adoption permitted at the beginning of an interim or annual reporting period. The Company adopted this ASU on January 1, 2017. The adoption of this ASU did not have a material impact on the Company's consolidated financial statements. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (“Standard”). The core principle of the Standard is for a company to recognize revenue for goods or services transferred to customers in an amount that reflects the consideration to which it expects to be entitled in exchange for those goods or services. To do so, a company will be required to exercise more judgment and make more estimates than under current guidance, including in identifying the performance obligations included in the arrangement, estimating and revising the variable consideration, if any, to be included in the transaction price and allocating the transaction price to distinct performance obligations. The FASB further clarified the Standard by issuing ASU No. 2016-10 (Identifying Performance Obligations and Licensing); ASU No. 2016-12 (Narrow-Scope Improvements and Practical Expedients); and ASU No. 2016-20 (Technical Corrections and Improvements). The Standard may be applied retrospectively to each prior period presented (full retrospective method) or retrospectively with the cumulative effect recognized as of the date of initial application (the modified retrospective method). The Standard, as amended, is effective for the company on January 1, 2018. As of June 30, 2017, the Company is determining which method to adopt, although the Company believes it will adopt the Standard using the full retrospective method which requires that the Standard be applied retrospectively to each prior period presented. The Company is currently finalizing its assessment of the impact the Standard will have on its consolidated financial statements, including disclosures, and expects that the Standard will materially impact the timing of revenue recognition for fixed or guaranteed minimums intellectual property ("IP") licensing arrangements as revenue could be recognized at a point in time, as opposed to when payments are due and payable under current guidance; the Company will also be required to compute and recognize interest income over time as control over the IP generally transfers significantly in advance of cash being received from customers. The Company will be required to recognize revenue on the basis of sales or usage based royalty estimates, with a true-up recorded in subsequent periods when licensees report actual sales or usage, as applicable. As part of the Company’s assessment and implementation plan, the Company is evaluating and implementing changes to its policies, procedures and controls.

Earnings (Loss) Per Share

Earnings (Loss) Per Share	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	Earnings Per Share Basic earnings per share is calculated by dividing the net income by the weighted average number of common shares outstanding during the period. Diluted earnings per share is calculated by dividing the earnings by the weighted average number of common shares and potentially dilutive securities outstanding during the period. Potentially dilutive common shares consist of incremental common shares issuable upon exercise of stock options, employee stock purchases, restricted stock and restricted stock units and shares issuable upon the conversion of convertible notes. The dilutive effect of outstanding shares is reflected in diluted earnings per share by application of the treasury stock method. This method includes consideration of the amounts to be paid by the employees and the amount of unrecognized stock-based compensation related to future services. No potential dilutive common shares are included in the computation of any diluted per share amount when a net loss is reported. The following table sets forth the computation of basic and diluted net income per share: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Net income per share: (In thousands, except per share amounts) Numerator: Net income $ 2,605 $ 3,876 $ 5,611 $ 5,754 Denominator: Weighted-average shares outstanding - basic 110,060 109,904 110,758 109,818 Effect of potential dilutive common shares 2,505 2,157 3,333 2,384 Weighted-average shares outstanding - diluted 112,565 112,061 114,091 112,202 Basic net income per share $ 0.02 $ 0.04 $ 0.05 $ 0.05 Diluted net income per share $ 0.02 $ 0.03 $ 0.05 $ 0.05 For the three months ended June 30, 2017 and 2016 , options to purchase approximately 2.0 million and 2.3 million shares, respectively, and for the six months ended June 30, 2017 and 2016 , options to purchase approximately 2.0 million and 2.3 million shares, respectively, were excluded from the calculation because they were anti-dilutive after considering proceeds from exercise and related unrecognized stock-based compensation expense.

Intangible Asset and Goodwill

Intangible Asset and Goodwill	6 Months Ended
	Jun. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Asset and Goodwill	Intangible Assets and Goodwill Goodwill The following tables present goodwill information for each of the reportable segments for the six months ended June 30, 2017 : Reportable Segment: As of December 31, 2016 Additions to Goodwill (1) Impairment of Goodwill Effect of Exchange Rates (2) As of June 30, 2017 (In thousands) MID $ 66,643 $ — $ — $ — $ 66,643 RSD 138,151 803 — 2,362 141,316 Total $ 204,794 $ 803 $ — $ 2,362 $ 207,959 (1) During the first quarter of 2017, the Company corrected an immaterial error related to an overstatement in prepaids and other current assets that originated in 2016. (2) Effect of exchange rates relates to foreign currency translation adjustments for the period. As of June 30, 2017 Reportable Segment: Gross Carrying Amount Accumulated Impairment Losses Net Carrying Amount (In thousands) MID $ 66,643 $ — $ 66,643 RSD 141,316 — 141,316 Other 21,770 (21,770 ) — Total $ 229,729 $ (21,770 ) $ 207,959 Intangible Assets The components of the Company’s intangible assets as of June 30, 2017 and December 31, 2016 were as follows: As of June 30, 2017 Useful Life Gross Carrying Amount (1) Accumulated Amortization Net Carrying Amount (In thousands) Existing technology 3 to 10 years $ 257,911 $ (174,539 ) $ 83,372 Customer contracts and contractual relationships 1 to 10 years 67,236 (43,833 ) 23,403 Non-compete agreements and trademarks 3 years 300 (300 ) — In-process research and development Not applicable 5,100 — 5,100 Total intangible assets $ 330,547 $ (218,672 ) $ 111,875 (1) The change in gross carrying amount reflects the effects of exchange rates during the period. As of December 31, 2016 Useful Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount (In thousands) Existing technology 3 to 10 years $ 256,656 $ (156,577 ) $ 100,079 Customer contracts and contractual relationships 1 to 10 years 65,109 (37,900 ) 27,209 Non-compete agreements and trademarks 3 years 300 (300 ) — In-process research and development Not applicable 5,100 — 5,100 Total intangible assets $ 327,165 $ (194,777 ) $ 132,388 During the three and six months ended June 30, 2017 , the Company did not purchase or sell any intangible assets. During the three and six months ended June 30, 2016 , the Company did not sell any intangible assets. Included in customer contracts and contractual relationships are favorable contracts which are acquired software and service agreements where the Company has no performance obligations. Cash received from these acquired favorable contracts reduces the favorable contract intangible asset. For the three months ended June 30, 2017 and 2016, the Company received $1.2 million and $2.4 million , respectively, related to the favorable contracts. For the six months ended June 30, 2017 and 2016, the Company received $2.4 million and $4.1 million , respectively, related to the favorable contracts. As of June 30, 2017 and December 31, 2016 , the net balance of the favorable contract intangible assets was $2.2 million and $3.6 million , respectively. Amortization expense for intangible assets for the three and six months ended June 30, 2017 was $10.5 million and $20.9 million , respectively. Amortization expense for intangible assets for the three and six months ended June 30, 2016 , was $8.2 million and $15.9 million , respectively. The estimated future amortization of intangible assets as of June 30, 2017 was as follows (amounts in thousands): Years Ending December 31: Amount 2017 (remaining 6 months) $ 22,174 2018 29,338 2019 19,594 2020 18,876 2021 12,500 Thereafter 9,393 $ 111,875 It is reasonably possible that the businesses could perform significantly below the Company's expectations or a deterioration of market and economic conditions could occur. This would adversely impact the Company's ability to meet its projected results, which could cause the goodwill in any of its reporting units or long-lived assets in any of its asset groups to become impaired. Significant differences between these estimates and actual cash flows could materially affect the Company's future financial results. If the Company determines that its goodwill or long-lived assets are impaired, it would be required to record a non-cash charge that could have a material adverse effect on its results of operations and financial position.

Segments and Major Customers

Segments and Major Customers	6 Months Ended
	Jun. 30, 2017
Segment Reporting [Abstract]
Segments and Major Customers	Segments and Major Customers For the three and six months ended June 30, 2017 , MID and RSD were reportable segments as each of them met the quantitative thresholds for disclosure as a reportable segment. The results of the remaining operating segments were shown under “Other.” The Company evaluates the performance of its segments based on segment operating income (loss), which is defined as revenue minus segment operating expenses. Segment operating expenses are comprised of direct operating expenses. Segment operating expenses do not include sales, general and administrative expenses and the allocation of certain expenses managed at the corporate level, such as stock-based compensation, amortization, and certain bonus and acquisition costs. The “Reconciling Items” category includes these unallocated sales, general and administrative expenses as well as corporate level expenses. The tables below present reported segment operating income (loss) for the three and six months ended June 30, 2017 and 2016 , respectively. For the Three Months Ended June 30, 2017 For the Six Months Ended June 30, 2017 MID RSD Other Total MID RSD Other Total (In thousands) (In thousands) Revenues $ 67,402 $ 23,366 $ 3,952 $ 94,720 $ 137,997 $ 46,571 $ 7,503 $ 192,071 Segment operating expenses 23,801 12,214 8,654 44,669 44,056 24,613 17,389 86,058 Segment operating income (loss) $ 43,601 $ 11,152 $ (4,702 ) $ 50,051 $ 93,941 $ 21,958 $ (9,886 ) $ 106,013 Reconciling items (41,807 ) (84,335 ) Operating income $ 8,244 $ 21,678 Interest and other income (expense), net (3,132 ) (6,184 ) Income before income taxes $ 5,112 $ 15,494 For the Three Months Ended June 30, 2016 For the Six Months Ended June 30, 2016 MID RSD Other Total MID RSD Other Total (In thousands) (In thousands) Revenues $ 54,467 $ 16,407 $ 5,627 $ 76,501 $ 108,012 $ 30,508 $ 10,663 $ 149,183 Segment operating expenses 13,229 13,105 7,092 33,426 25,272 25,015 14,218 64,505 Segment operating income (loss) $ 41,238 $ 3,302 $ (1,465 ) $ 43,075 $ 82,740 $ 5,493 $ (3,555 ) $ 84,678 Reconciling items (31,067 ) (63,376 ) Operating income $ 12,008 $ 21,302 Interest and other income (expense), net (2,025 ) (4,924 ) Income before income taxes $ 9,983 $ 16,378 The Company’s CODM does not review information regarding assets on an operating segment basis. Additionally, the Company does not record intersegment revenue or expense. Accounts receivable from the Company's major customers representing 10% or more of total accounts receivable at June 30, 2017 and December 31, 2016 , respectively, was as follows: As of Customer June 30, 2017 December 31, 2016 Customer 1 (RSD reportable segment) * 17 % Customer 2 (Other segment) * 12 % Customer 3 (MID reportable segment) 20 % 13 % Customer 4 (MID reportable segment) 25 % * _________________________________________ * Customer accounted for less than 10% of total accounts receivable in the period Revenue from the Company’s major customers representing 10% or more of total revenue for the three and six months ended June 30, 2017 and 2016 , respectively, was as follows: Three Months Ended Six Months Ended June 30, June 30, Customer 2017 2016 2017 2016 Customer A (MID and RSD reportable segments) 17 % 20 % 17 % 21 % Customer B (MID reportable segment) 13 % 21 % 13 % 21 % Customer C (MID reportable segment) 14 % 13 % 14 % 13 % Revenue from customers in the geographic regions based on the location of contracting parties was as follows: Three Months Ended Six Months Ended June 30, June 30, (In thousands) 2017 2016 2017 2016 South Korea $ 28,291 $ 31,632 $ 57,260 $ 63,086 USA 41,155 26,532 79,593 51,776 Japan 7,057 5,911 13,575 10,898 Europe 4,243 4,377 8,681 8,189 Canada 1,352 1,168 2,420 1,382 Singapore 4,889 4,526 12,636 9,145 Asia-Other 7,733 2,355 17,906 4,707 Total $ 94,720 $ 76,501 $ 192,071 $ 149,183

Marketable Securities

Marketable Securities	6 Months Ended
	Jun. 30, 2017
Available-for-sale Securities [Abstract]
Marketable Securities	Marketable Securities Rambus invests its excess cash and cash equivalents primarily in U.S. government-sponsored obligations, commercial paper, corporate notes and bonds, money market funds and municipal notes and bonds that mature within three years. As of June 30, 2017 and December 31, 2016 , all of the Company’s cash equivalents and marketable securities had a remaining maturity of less than one year . All cash equivalents and marketable securities are classified as available-for-sale. Total cash, cash equivalents and marketable securities are summarized as follows: As of June 30, 2017 (In thousands) Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Weighted Rate of Return Money market funds $ 15,460 $ 15,460 $ — $ — 0.83 % U.S. Government bonds and notes 63,612 63,610 2 — 0.83 % Corporate notes, bonds, commercial paper and other 37,754 37,758 — (4 ) 0.97 % Total cash equivalents and marketable securities 116,826 116,828 2 (4 ) Cash 51,127 51,127 — — Total cash, cash equivalents and marketable securities $ 167,953 $ 167,955 $ 2 $ (4 ) As of December 31, 2016 (In thousands) Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Weighted Rate of Return Money market funds $ 10,681 $ 10,681 $ — $ — 0.41 % U.S. Government bonds and notes 48,292 48,291 1 — 0.39 % Corporate notes, bonds, commercial paper and other 62,178 62,199 — (21 ) 0.66 % Total cash equivalents and marketable securities 121,151 121,171 1 (21 ) Cash 51,031 51,031 — — Total cash, cash equivalents and marketable securities $ 172,182 $ 172,202 $ 1 $ (21 ) Available-for-sale securities are reported at fair value on the balance sheets and classified as follows: As of June 30, December 31, (In thousands) Cash equivalents $ 116,080 $ 84,263 Short term marketable securities 746 36,888 Total cash equivalents and marketable securities 116,826 121,151 Cash 51,127 51,031 Total cash, cash equivalents and marketable securities $ 167,953 $ 172,182 The Company continues to invest in highly rated quality, highly liquid debt securities. As of June 30, 2017 , these securities have a remaining maturity of less than one year. The Company holds all of its marketable securities as available-for-sale, marks them to market, and regularly reviews its portfolio to ensure adherence to its investment policy and to monitor individual investments for risk analysis, proper valuation, and unrealized losses that may be other than temporary. The estimated fair value of cash equivalents and marketable securities classified by the length of time that the securities have been in a continuous unrealized loss position at June 30, 2017 and December 31, 2016 are as follows: Fair Value Gross Unrealized Loss June 30, December 31, June 30, December 31, (In thousands) Less than one year U.S. Government bonds and notes $ 8,997 $ 18,395 $ — $ — Corporate notes, bonds and commercial paper 33,668 54,377 (4 ) (21 ) Total Corporate notes, bonds, and commercial paper and U.S. Government bonds and notes $ 42,665 $ 72,772 $ (4 ) $ (21 ) The gross unrealized loss at June 30, 2017 and December 31, 2016 was not material in relation to the Company’s total available-for-sale portfolio. The gross unrealized loss can be primarily attributed to a combination of market conditions as well as the demand for and duration of the U.S. government-sponsored obligations and corporate notes and bonds. There is no need to sell these investments, and the Company believes that it can recover the amortized cost of these investments. The Company has found no evidence of impairment due to credit losses in its portfolio. Therefore, these unrealized losses were recorded in other comprehensive income. However, the Company cannot provide any assurance that its portfolio of cash, cash equivalents and marketable securities will not be impacted by adverse conditions in the financial markets, which may require the Company in the future to record an impairment charge for credit losses which could adversely impact its financial results. See Note 7, “Fair Value of Financial Instruments,” for discussion regarding the fair value of the Company’s cash equivalents and marketable securities.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company reviews the pricing inputs by obtaining prices from a different source for the same security on a sample of its portfolio. The Company has not adjusted the pricing inputs it has obtained. The following table presents the financial instruments that are carried at fair value and summarizes the valuation of its cash equivalents and marketable securities by the above pricing levels as of June 30, 2017 and December 31, 2016 : As of June 30, 2017 Total Quoted Market Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In thousands) Money market funds $ 15,460 $ 15,460 $ — $ — U.S. Government bonds and notes 63,612 — 63,612 — Corporate notes, bonds, commercial paper and other 37,754 746 37,008 — Total available-for-sale securities $ 116,826 $ 16,206 $ 100,620 $ — As of December 31, 2016 Total Quoted Market Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In thousands) Money market funds $ 10,681 $ 10,681 $ — $ — U.S. Government bonds and notes 48,292 — 48,292 — Corporate notes, bonds, commercial paper and other 62,178 303 61,875 — Total available-for-sale securities $ 121,151 $ 10,984 $ 110,167 $ — The Company monitors its investments for other-than-temporary impairment and records appropriate reductions in carrying value when necessary. The Company monitors its investments for other-than-temporary losses by considering current factors, including the economic environment, market conditions, operational performance and other specific factors relating to the business underlying the investment, reductions in carrying values when necessary and the Company’s ability and intent to hold the investment for a period of time which may be sufficient for anticipated recovery in the market. Any other-than-temporary loss is reported under “Interest and other income (expense), net” in the condensed consolidated statement of operations. For the three and six months ended June 30, 2017 and 2016 , there were no transfers of financial instruments between different categories of fair value. The following table presents the financial instruments that are not carried at fair value but require fair value disclosure as of June 30, 2017 and December 31, 2016 : As of June 30, 2017 As of December 31, 2016 (In thousands) Face Value Carrying Value Fair Value Face Value Carrying Value Fair Value 1.125% Convertible Senior Notes due 2018 (the "2018 Notes") $ 138,000 $ 129,690 $ 151,386 $ 138,000 $ 126,167 $ 173,961 The fair value of the convertible notes at each balance sheet date is determined based on recent quoted market prices for these notes which is a level 2 measurement. As discussed in Note 8, "Convertible Notes," as of June 30, 2017 , the 2018 Notes are carried at their face value of $138.0 million , less any unamortized debt discount and unamortized debt issuance costs. The carrying value of other financial instruments, including accounts receivable, accounts payable and other liabilities, approximates fair value due to their short maturities.

Convertible Notes

Convertible Notes	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
Convertible Notes	Convertible Notes The Company’s convertible notes are shown in the following table: (In thousands) As of June 30, 2017 As of December 31, 2016 1.125% Convertible Senior Notes due 2018 $ 138,000 $ 138,000 Unamortized discount (7,673 ) (10,913 ) Unamortized debt issuance costs (637 ) (920 ) Total convertible notes $ 129,690 $ 126,167 Less current portion — — Total long-term convertible notes $ 129,690 $ 126,167 Interest expense related to the notes for the three and six months ended June 30, 2017 and 2016 was as follows: Three Months Ended Six Months Ended June 30, June 30, 2017 2016 2017 2016 (In thousands) 2018 Notes coupon interest at a rate of 1.125% $ 388 $ 388 776 776 2018 Notes amortization of discount and debt issuance costs at an additional effective interest rate of 5.5% 1,774 1,675 3,523 3,326 Total interest expense on convertible notes $ 2,162 $ 2,063 $ 4,299 $ 4,102

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies As of June 30, 2017 , the Company’s material contractual obligations were as follows (in thousands): Total Remainder of 2017 2018 2019 2020 2021 Thereafter Contractual obligations (1) Imputed financing obligation (2) $ 19,103 $ 3,185 $ 6,447 $ 6,602 $ 2,869 $ — $ — Leases and other contractual obligations 18,784 4,213 4,569 3,514 2,549 2,646 1,293 Software licenses (3) 18,557 4,849 10,176 3,532 — — — Convertible notes 138,000 — 138,000 — — — — Interest payments related to convertible notes 2,328 776 1,552 — — — — Total $ 196,772 $ 13,023 $ 160,744 $ 13,648 $ 5,418 $ 2,646 $ 1,293 _________________________________________ (1) The above table does not reflect possible payments in connection with uncertain tax benefits of approximately $22.9 million including $20.7 million recorded as a reduction of long-term deferred tax assets and $2.2 million in long-term income taxes payable as of June 30, 2017 . As noted below in Note 12, “Income Taxes,” although it is possible that some of the unrecognized tax benefits could be settled within the next 12 months, the Company cannot reasonably estimate the outcome at this time. (2) With respect to the imputed financing obligation, the main components of the difference between the amount reflected in the contractual obligations table and the amount reflected on the unaudited condensed consolidated balance sheets are the interest on the imputed financing obligation and the estimated common area expenses over the future periods. The amount includes the amended Ohio lease and the amended Sunnyvale lease. (3) The Company has commitments with various software vendors for non-cancellable agreements generally having terms longer than one year. Building lease expense was approximately $1.1 million and $2.1 million for the three and six months ended June 30, 2017 , respectively. Building lease expense was approximately $0.9 million and $1.7 million for the three and six months ended June 30, 2016 , respectively. Deferred rent of $0.3 million and $0.5 million as of June 30, 2017 and December 31, 2016 , respectively, was included primarily in other current liabilities. Indemnification From time to time, the Company indemnifies certain customers as a necessary means of doing business. Indemnification covers customers for losses suffered or incurred by them as a result of any patent, copyright, or other intellectual property infringement or any other claim by any third party arising as result of the applicable agreement with the Company. The Company generally attempts to limit the maximum amount of indemnification or liability that the Company could be exposed to under these agreements, however, this is not always possible. The fair value of the liability as of June 30, 2017 and December 31, 2016 is not material.

Equity Incentive Plans and Stoc

Equity Incentive Plans and Stock-Based Compensation	6 Months Ended
	Jun. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Incentive Plans and Stock-Based Compensation	Equity Incentive Plans and Stock-Based Compensation As of June 30, 2017 , 5,440,093 shares of the 35,400,000 cumulative shares approved under both the current 2015 Equity Incentive Plan (the “2015 Plan”) and past 2006 Equity Incentive Plan (the “2006 Plan”) remain available for grant, which included an increase of 4,000,000 shares approved under the 2015 Plan. On April 23, 2015, the Company's stockholders approved the 2015 Plan, which authorizes 4,000,000 shares for future issuance plus the number of shares that remained available for grant under the 2006 Plan as of the effective date of the 2015 Plan. The 2015 Plan became effective and replaced the 2006 Plan on April 23, 2015. The 2015 Plan was the Company’s only plan for providing stock-based incentive awards to eligible employees, executive officers, non-employee directors and consultants as of June 30, 2017 . No further awards will be made under the 2006 Plan, but the 2006 Plan will continue to govern awards previously granted under it. In addition, any shares subject to stock options or other awards granted under the 2006 Plan that on or after the effective date of the 2015 Plan are forfeited, cancelled, exchanged or surrendered or terminate under the 2006 Plan will become available for grant under the 2015 Plan. A summary of shares available for grant under the Company’s plans is as follows: Shares Available for Grant Shares available as of December 31, 2016 7,305,368 Stock options granted (498,426 ) Stock options forfeited 1,472,366 Nonvested equity stock and stock units granted (1) (2) (3,553,590 ) Nonvested equity stock and stock units forfeited (1) 714,375 Total available for grant as of June 30, 2017 5,440,093 _________________________________________ (1) For purposes of determining the number of shares available for grant under the 2015 Plan against the maximum number of shares authorized, each share of restricted stock granted reduces the number of shares available for grant by 1.5 shares and each share of restricted stock forfeited increases shares available for grant by 1.5 shares. (2) Amount includes 266,847 shares that have been reserved for potential future issuance related to certain performance unit awards granted in the first quarter of 2017 and discussed under the section titled "Nonvested Equity Stock and Stock Units" below. General Stock Option Information The following table summarizes stock option activity under the 2006 Plan and 2015 Plan for the six months ended June 30, 2017 and information regarding stock options outstanding, exercisable, and vested and expected to vest as of June 30, 2017 . Options Outstanding Number of Shares Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term (years) Aggregate Intrinsic Value (In thousands, except per share amounts) Outstanding as of December 31, 2016 7,008,833 $ 9.34 Options granted 498,426 $ 12.74 Options exercised (654,388 ) $ 7.04 Options forfeited (1,472,366 ) $ 10.95 Outstanding as of June 30, 2017 5,380,505 $ 9.49 5.48 $ 16,061 Vested or expected to vest at June 30, 2017 5,297,443 $ 9.45 5.43 $ 16,037 Options exercisable at June 30, 2017 3,874,169 $ 9.20 4.58 $ 13,287 No stock options that contain a market condition were granted during the three and six months ended June 30, 2017 . As of June 30, 2017 and December 31, 2016 , there were 320,000 and 1,135,000 , respectively, stock options outstanding that require the Company to achieve minimum market conditions in order for the options to become exercisable. The fair values of the options granted with a market condition were calculated, on their respective grant dates, using a binomial valuation model, which estimates the potential outcome of reaching the market condition based on simulated future stock prices. The aggregate intrinsic value in the table above represents the total pre-tax intrinsic value for in-the-money options at June 30, 2017 , based on the $11.43 closing stock price of Rambus’ common stock on June 30, 2017 on the NASDAQ Global Select Market, which would have been received by the option holders had all option holders exercised their options as of that date. The total number of in-the-money options outstanding and exercisable as of June 30, 2017 was 3,703,530 and 3,063,509 , respectively. Employee Stock Purchase Plan Under the 2015 Employee Stock Purchase Plan ("2015 ESPP"), the Company issued 361,994 shares at a price of $10.33 per share during the six months ended June 30, 2017 . Under the 2015 ESPP, the Company issued 340,349 shares at a price of $8.96 per share during the six months ended June 30, 2016 . As of June 30, 2017 , 1,089,649 shares under the 2015 ESPP remain available for issuance. Stock-Based Compensation For the six months ended June 30, 2017 and 2016 , the Company maintained stock plans covering a broad range of potential equity grants including stock options, nonvested equity stock and equity stock units and performance based instruments. In addition, the Company sponsors the 2015 ESPP, whereby eligible employees are entitled to purchase common stock semi-annually, by means of limited payroll deductions, at a 15% discount from the fair market value of the common stock as of specific dates. Stock Options During the three months ended June 30, 2017 , the Company granted 40,000 stock options with an estimated total grant-date fair value of $0.2 million . During the six months ended June 30, 2017, the Company granted 498,426 stock options with an estimated total grant-date fair value of $2.1 million . During the three and six months ended June 30, 2017 , the Company recorded stock-based compensation expense related to stock options of $0.7 million and $1.4 million , respectively. During the three months ended June 30, 2016 , the Company did not grant any stock options. During the six months ended June 30, 2016 , the Company granted 440,000 stock options with an estimated total grant-date fair value of $2.1 million . During the three and six months ended June 30, 2016 , the Company recorded stock-based compensation expense related to stock options of $1.1 million and $2.3 million , respectively. As of June 30, 2017 , there was $4.9 million of total unrecognized compensation cost, net of expected forfeitures, related to non-vested stock-based compensation arrangements granted under the stock option plans. That cost is expected to be recognized over a weighted-average period of 2.0 years. The total fair value of shares vested as of June 30, 2017 was $20.7 million . The total intrinsic value of options exercised was $1.8 million and $3.8 million for the three and six months ended June 30, 2017 , respectively. The total intrinsic value of options exercised was $0.9 million and $4.0 million for the three and six months ended June 30, 2016 , respectively. Intrinsic value is the total value of exercised shares based on the price of the Company’s common stock at the time of exercise less the cash received from the employees to exercise the options. During the six months ended June 30, 2017 , net proceeds from employee stock option exercises totaled approximately $4.6 million . Employee Stock Purchase Plan For the three and six months ended June 30, 2017 , the Company recorded compensation expense related to the 2015 ESPP of $0.4 million and $0.9 million , respectively. For the three and six months ended June 30, 2016 , the Company recorded compensation expense related to the 2015 ESPP of $0.3 million and $0.8 million , respectively. As of June 30, 2017 , there was $0.5 million of total unrecognized compensation cost related to stock-based compensation arrangements granted under the 2015 ESPP. That cost is expected to be recognized over four months. Tax benefits realized as a result of employee stock option exercises, stock purchase plan purchases, and vesting of equity stock and stock units for the three and six months ended June 30, 2017 calculated in accordance with accounting for share-based payments were $0.2 million and $0.5 million , respectively. There were no tax benefits realized as a result of employee stock option exercises, stock purchase plan purchases, and vesting of equity stock and stock units for the three and six months ended June 30, 2016 calculated in accordance with accounting for share-based payments. Valuation Assumptions The fair value of stock awards is estimated as of the grant date using the Black-Scholes-Merton (“BSM”) option-pricing model assuming a dividend yield of 0% and the additional weighted-average assumptions as listed in the table below. The following table presents the weighted-average assumptions used to estimate the fair value of stock options granted that contain only service conditions in the periods presented. Stock Option Plan Three Months Ended Six Months Ended June 30, June 30, 2017 2016 2017 2016 Stock Option Plan Expected stock price volatility 32 % — % 32 % 36 % Risk free interest rate 1.8 % — % 1.8% - 1.9% 1.7 % Expected term (in years) 5.3 — 5.3 - 5.4 6.1 Weighted-average fair value of stock options granted to employees $ 3.84 $ — $ 4.12 $ 4.66 There were no stock options granted during the three months ended June 30, 2016 . Employee Stock Purchase Plan Six Months Ended June 30, 2017 2016 Employee Stock Purchase Plan Expected stock price volatility 27 % 33 % Risk free interest rate 0.98 % 0.41 % Expected term (in years) 0.5 0.5 Weighted-average fair value of purchase rights granted under the purchase plan $ 2.87 $ 2.86 Nonvested Equity Stock and Stock Units The Company grants nonvested equity stock units to officers, employees and directors. During the three and six months ended June 30, 2017 , the Company granted nonvested equity stock units totaling 151,354 and 2,191,162 shares under the 2015 Plan. During the three and six months ended June 30, 2016 , the Company granted nonvested equity stock units totaling 184,456 and 2,024,640 shares under the 2015 Plan. These awards have a service condition, generally a service period of four years , except in the case of grants to directors, for which the service period is 1 year . For the three and six months ended June 30, 2017 , the nonvested equity stock units were valued at the date of grant giving them a fair value of approximately $1.9 million and $28.1 million . For the three and six months ended June 30, 2016 , the nonvested equity stock units were valued at the date of grant giving them a fair value of approximately $2.3 million and $25.0 million . During the first quarters of 2017 and 2016, the Company granted performance unit awards to certain Company executive officers with vesting subject to the achievement of certain performance conditions. The ultimate number of performance units that can be earned can range from 0% to 150% of target depending on performance relative to target over the applicable period. The shares earned will vest on the third anniversary of the date of grant. The Company's shares available for grant has been reduced to reflect the shares that could be earned at 150% of target. During the three and six months ended June 30, 2017 , the Company recorded $1.0 million and $1.9 million , respectively, of stock-based compensation expense related to these performance unit awards. During the three and six months ended June 30, 2016 , the Company recorded $0.7 million and $1.3 million , respectively, of stock-based compensation expense related to these performance unit awards. For the three and six months ended June 30, 2017 , the Company recorded stock-based compensation expense of approximately $5.5 million and $10.8 million related to all outstanding nonvested equity stock grants. For the three and six months ended June 30, 2016 , the Company recorded stock-based compensation expense of approximately $3.7 million and $6.8 million related to all outstanding nonvested equity stock grants. Unrecognized stock-based compensation related to all nonvested equity stock grants, net of estimated forfeitures, was approximately $48.9 million at June 30, 2017 . This amount is expected to be recognized over a weighted average period of 2.7 years . The following table reflects the activity related to nonvested equity stock and stock units for the six months ended June 30, 2017 : Nonvested Equity Stock and Stock Units Shares Weighted- Average Grant-Date Fair Value Nonvested at December 31, 2016 4,863,056 $ 12.33 Granted 2,191,162 $ 12.81 Vested (615,671 ) $ 11.59 Forfeited (450,339 ) $ 12.54 Nonvested at June 30, 2017 5,988,208 $ 12.57

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2017
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Stockholders’ Equity Share Repurchase Program During the six months ended June 30, 2017 , the Company repurchased shares of its common stock under its share repurchase program as discussed below. On January 21, 2015, the Company's Board approved a share repurchase program authorizing the repurchase of up to an aggregate of 20.0 million shares. Share repurchases under the plan may be made through the open market, established plans or privately negotiated transactions in accordance with all applicable securities laws, rules, and regulations. There is no expiration date applicable to the plan. On May 1, 2017, the Company initiated an accelerated share repurchase program with Barclays Bank PLC. The accelerated share repurchase program is part of the broader share repurchase program previously authorized by the Company's Board on January 21, 2015. Under the accelerated share repurchase program, the Company pre-paid to Barclays Bank PLC, the $50.0 million purchase price for its common stock and, in turn, the Company received an initial delivery of approximately 3.2 million shares of its common stock from Barclays Bank PLC, in the second quarter of 2017, which were retired and recorded as a $40.0 million reduction to stockholders' equity. The remaining $10.0 million of the initial payment was recorded as a reduction to stockholders’ equity as an unsettled forward contract indexed to the Company's stock. The number of shares to be ultimately purchased by the Company will be determined based on the volume weighted average price of the common stock during the terms of the transaction, minus an agreed upon discount between the parties. The program is expected to be completed by November 2017. As of June 30, 2017 , there remained an outstanding authorization to repurchase approximately 8.3 million shares of the Company's outstanding common stock under the current share repurchase program. The Company records stock repurchases as a reduction to stockholders’ equity. The Company records a portion of the purchase price of the repurchased shares as an increase to accumulated deficit when the price of the shares repurchased exceeds the average original proceeds per share received from the issuance of common stock. During the six months ended June 30, 2017, the cumulative price of $29.4 million was recorded as an increase to accumulated deficit.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company recorded a provision for income taxes of $2.5 million and $6.1 million for the three months ended June 30, 2017 and 2016 , respectively, and $9.9 million and $10.6 million for the six months ended June 30, 2017 and 2016 , respectively. The income taxes for the three and six months ended June 30, 2017 is primarily comprised of the Company's U.S. federal, state and foreign taxes and income tax expense recognized from exercises and expiration of out-of-the-money fully vested shares from equity incentive plans. Similarly, the income taxes for the three and six months ended June 30, 2016 was primarily comprised of the Company's U.S. federal, state and foreign taxes and income tax expense recognized from exercises and expiration of shares from equity incentive plans. During the three and six months ended June 30, 2017 , the Company paid withholding taxes of $5.4 million and $10.9 million , respectively. During the three and six months ended June 30, 2016 , the Company paid withholding taxes of $5.4 million and $10.9 million , respectively. As of June 30, 2017 , the Company’s unaudited condensed consolidated balance sheets included net deferred tax assets, before valuation allowance, of approximately $219.5 million , which consists of net operating loss carryovers, tax credit carryovers, amortization, employee stock-based compensation expenses and certain liabilities, partially reduced by deferred tax liabilities associated with the convertible notes. The Company has U.S. federal deferred tax assets related to research and development credits, foreign tax credits and other tax attributes that can be used to offset federal taxable income in future periods. These credit carryforwards will expire if they are not used within certain time periods. As of June 30, 2017 , the Company determined that there is sufficient positive evidence to conclude that it is more likely than not sufficient taxable income will exist in the future allowing the Company to recognize these deferred tax assets. It is possible that some or all these attributes could ultimately expire unused. If facts and circumstances change in the future, the Company may determine at that time a valuation allowance is necessary. A valuation allowance would materially increase the Company's tax expense in the period applied and would adversely affect its results of operations and statements of financial condition. Changes in the Company's underlying facts or circumstances, such as the impact of the acquisitions, will be continually assessed and the Company will re-evaluate its position accordingly. As of June 30, 2017 , the Company continues to maintain a valuation allowance against the majority of its state deferred tax assets. Management periodically evaluates the realizability of the Company's net deferred tax assets based on all available evidence, both positive and negative. The realizability of the Company's net deferred tax assets is dependent on its ability to generate sufficient future taxable income during periods prior to the expiration of tax attributes to fully utilize these assets. The Company continues to maintain a deferred tax asset valuation allowance of $26.2 million as of June 30, 2017 . The Company maintains liabilities for uncertain tax positions within its long-term income taxes payable accounts and as a reduction to existing deferred tax assets to the extent tax attributes are available to offset such liabilities. These liabilities involve judgment and estimation and are monitored by management based on the best information available including changes in tax regulations, the outcome of relevant court cases and other information. As of June 30, 2017 , the Company had approximately $22.9 million of unrecognized tax benefits, including $20.7 million recorded as a reduction of long-term deferred tax assets and $2.2 million in long-term income taxes payable. If recognized, approximately $2.2 million would be recorded as an income tax benefit. As of December 31, 2016 , the Company had $21.9 million of unrecognized tax benefits, including $19.7 million recorded as a reduction of long-term deferred tax assets and $2.2 million recorded in long-term income taxes payable. Although it is possible that some of the unrecognized tax benefits could be settled within the next 12 months, the Company cannot reasonably estimate the outcome at this time. The Company recognizes interest and penalties related to uncertain tax positions as a component of the income tax provision. At June 30, 2017 and December 31, 2016 , an immaterial amount of interest and penalties is included in long-term income taxes payable. Rambus files income tax returns for the U.S., California, India, the U.K., the Netherlands and various other state and foreign jurisdictions. The U.S. federal returns are subject to examination from 2013 and forward. The California returns are subject to examination from 2010 and forward. In addition, any research and development credit carryforward or net operating loss carryforward generated in prior years and utilized in these or future years may also be subject to examination. The India returns are subject to examination from fiscal year ending March 2012 and forward. The Company is currently under examination by California for the 2010 and 2011 tax years and New York for the 2013, 2014 and 2015 tax years. The Company’s India subsidiary is under examination by the Indian tax administration for tax years beginning with 2011, except for 2014, which was assessed in the Company's favor. These examinations may result in proposed adjustments to the income taxes as filed during these periods. Management regularly assesses the likelihood of outcomes resulting from income tax examinations to determine the adequacy of their provision for income taxes and believes their provision for unrecognized tax benefits is adequate. Additionally, the Company's future effective tax rates could be adversely affected by earnings being higher than anticipated in countries where the Company has higher statutory rates or lower than anticipated in countries where it has lower statutory rates, by changes in valuation of its deferred tax assets and liabilities or by changes in tax laws or interpretations of those laws.

Litigation and Asserted Claims

Litigation and Asserted Claims	6 Months Ended
	Jun. 30, 2017
LitigationAndAssertedClaimsDisclosureAbstract
Litigation and Asserted Claims	Litigation and Asserted Claims Rambus is not currently a party to any material pending legal proceeding; however, from time to time, Rambus may become involved in legal proceedings or be subject to claims arising in the ordinary course of its business. Although the results of litigation and claims cannot be predicted with certainty, the Company currently believes that the final outcome of these ordinary course matters will not have a material adverse effect on our business, operating results, financial position or cash flows. Regardless of the outcome, litigation can have an adverse impact on the Company because of defense and settlement costs, diversion of management resources and other factors. The Company records a contingent liability when it is probable that a loss has been incurred and the amount is reasonably estimable in accordance with accounting for contingencies.

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Computation of basic and diluted loss per share	The following table sets forth the computation of basic and diluted net income per share: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Net income per share: (In thousands, except per share amounts) Numerator: Net income $ 2,605 $ 3,876 $ 5,611 $ 5,754 Denominator: Weighted-average shares outstanding - basic 110,060 109,904 110,758 109,818 Effect of potential dilutive common shares 2,505 2,157 3,333 2,384 Weighted-average shares outstanding - diluted 112,565 112,061 114,091 112,202 Basic net income per share $ 0.02 $ 0.04 $ 0.05 $ 0.05 Diluted net income per share $ 0.02 $ 0.03 $ 0.05 $ 0.05

Intangible Asset and Goodwill (

Intangible Asset and Goodwill (Tables)	6 Months Ended
	Jun. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of changes in carrying amount of goodwill by reporting unit	The following tables present goodwill information for each of the reportable segments for the six months ended June 30, 2017 : Reportable Segment: As of December 31, 2016 Additions to Goodwill (1) Impairment of Goodwill Effect of Exchange Rates (2) As of June 30, 2017 (In thousands) MID $ 66,643 $ — $ — $ — $ 66,643 RSD 138,151 803 — 2,362 141,316 Total $ 204,794 $ 803 $ — $ 2,362 $ 207,959 (1) During the first quarter of 2017, the Company corrected an immaterial error related to an overstatement in prepaids and other current assets that originated in 2016. (2) Effect of exchange rates relates to foreign currency translation adjustments for the period. As of June 30, 2017 Reportable Segment: Gross Carrying Amount Accumulated Impairment Losses Net Carrying Amount (In thousands) MID $ 66,643 $ — $ 66,643 RSD 141,316 — 141,316 Other 21,770 (21,770 ) — Total $ 229,729 $ (21,770 ) $ 207,959
Components of intangible assets	The components of the Company’s intangible assets as of June 30, 2017 and December 31, 2016 were as follows: As of June 30, 2017 Useful Life Gross Carrying Amount (1) Accumulated Amortization Net Carrying Amount (In thousands) Existing technology 3 to 10 years $ 257,911 $ (174,539 ) $ 83,372 Customer contracts and contractual relationships 1 to 10 years 67,236 (43,833 ) 23,403 Non-compete agreements and trademarks 3 years 300 (300 ) — In-process research and development Not applicable 5,100 — 5,100 Total intangible assets $ 330,547 $ (218,672 ) $ 111,875 (1) The change in gross carrying amount reflects the effects of exchange rates during the period. As of December 31, 2016 Useful Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount (In thousands) Existing technology 3 to 10 years $ 256,656 $ (156,577 ) $ 100,079 Customer contracts and contractual relationships 1 to 10 years 65,109 (37,900 ) 27,209 Non-compete agreements and trademarks 3 years 300 (300 ) — In-process research and development Not applicable 5,100 — 5,100 Total intangible assets $ 327,165 $ (194,777 ) $ 132,388
Estimated future amortization expense of intangible assets	The estimated future amortization of intangible assets as of June 30, 2017 was as follows (amounts in thousands): Years Ending December 31: Amount 2017 (remaining 6 months) $ 22,174 2018 29,338 2019 19,594 2020 18,876 2021 12,500 Thereafter 9,393 $ 111,875

Segments and Major Customers (T

Segments and Major Customers (Tables)	6 Months Ended
	Jun. 30, 2017
Concentration Risk [Line Items]
Reported segment revenues, and reported segment direct operating income (loss)	The tables below present reported segment operating income (loss) for the three and six months ended June 30, 2017 and 2016 , respectively. For the Three Months Ended June 30, 2017 For the Six Months Ended June 30, 2017 MID RSD Other Total MID RSD Other Total (In thousands) (In thousands) Revenues $ 67,402 $ 23,366 $ 3,952 $ 94,720 $ 137,997 $ 46,571 $ 7,503 $ 192,071 Segment operating expenses 23,801 12,214 8,654 44,669 44,056 24,613 17,389 86,058 Segment operating income (loss) $ 43,601 $ 11,152 $ (4,702 ) $ 50,051 $ 93,941 $ 21,958 $ (9,886 ) $ 106,013 Reconciling items (41,807 ) (84,335 ) Operating income $ 8,244 $ 21,678 Interest and other income (expense), net (3,132 ) (6,184 ) Income before income taxes $ 5,112 $ 15,494 For the Three Months Ended June 30, 2016 For the Six Months Ended June 30, 2016 MID RSD Other Total MID RSD Other Total (In thousands) (In thousands) Revenues $ 54,467 $ 16,407 $ 5,627 $ 76,501 $ 108,012 $ 30,508 $ 10,663 $ 149,183 Segment operating expenses 13,229 13,105 7,092 33,426 25,272 25,015 14,218 64,505 Segment operating income (loss) $ 41,238 $ 3,302 $ (1,465 ) $ 43,075 $ 82,740 $ 5,493 $ (3,555 ) $ 84,678 Reconciling items (31,067 ) (63,376 ) Operating income $ 12,008 $ 21,302 Interest and other income (expense), net (2,025 ) (4,924 ) Income before income taxes $ 9,983 $ 16,378
Revenue from external customer by geographic regions	Revenue from customers in the geographic regions based on the location of contracting parties was as follows: Three Months Ended Six Months Ended June 30, June 30, (In thousands) 2017 2016 2017 2016 South Korea $ 28,291 $ 31,632 $ 57,260 $ 63,086 USA 41,155 26,532 79,593 51,776 Japan 7,057 5,911 13,575 10,898 Europe 4,243 4,377 8,681 8,189 Canada 1,352 1,168 2,420 1,382 Singapore 4,889 4,526 12,636 9,145 Asia-Other 7,733 2,355 17,906 4,707 Total $ 94,720 $ 76,501 $ 192,071 $ 149,183
Accounts Receivable [Member]
Concentration Risk [Line Items]
Schedule of customer accounts representing 10% or more than 10% of total revenue	Accounts receivable from the Company's major customers representing 10% or more of total accounts receivable at June 30, 2017 and December 31, 2016 , respectively, was as follows: As of Customer June 30, 2017 December 31, 2016 Customer 1 (RSD reportable segment) * 17 % Customer 2 (Other segment) * 12 % Customer 3 (MID reportable segment) 20 % 13 % Customer 4 (MID reportable segment) 25 % * _________________________________________ * Customer accounted for less than 10% of total accounts receivable in the period
Sales, net
Concentration Risk [Line Items]
Schedule of customer accounts representing 10% or more than 10% of total revenue	Revenue from the Company’s major customers representing 10% or more of total revenue for the three and six months ended June 30, 2017 and 2016 , respectively, was as follows: Three Months Ended Six Months Ended June 30, June 30, Customer 2017 2016 2017 2016 Customer A (MID and RSD reportable segments) 17 % 20 % 17 % 21 % Customer B (MID reportable segment) 13 % 21 % 13 % 21 % Customer C (MID reportable segment) 14 % 13 % 14 % 13 %

Marketable Securities (Tables)

Marketable Securities (Tables)	6 Months Ended
	Jun. 30, 2017
Available-for-sale Securities [Abstract]
Cash equivalents and marketable securities classified as available-for-sale	All cash equivalents and marketable securities are classified as available-for-sale. Total cash, cash equivalents and marketable securities are summarized as follows: As of June 30, 2017 (In thousands) Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Weighted Rate of Return Money market funds $ 15,460 $ 15,460 $ — $ — 0.83 % U.S. Government bonds and notes 63,612 63,610 2 — 0.83 % Corporate notes, bonds, commercial paper and other 37,754 37,758 — (4 ) 0.97 % Total cash equivalents and marketable securities 116,826 116,828 2 (4 ) Cash 51,127 51,127 — — Total cash, cash equivalents and marketable securities $ 167,953 $ 167,955 $ 2 $ (4 ) As of December 31, 2016 (In thousands) Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Weighted Rate of Return Money market funds $ 10,681 $ 10,681 $ — $ — 0.41 % U.S. Government bonds and notes 48,292 48,291 1 — 0.39 % Corporate notes, bonds, commercial paper and other 62,178 62,199 — (21 ) 0.66 % Total cash equivalents and marketable securities 121,151 121,171 1 (21 ) Cash 51,031 51,031 — — Total cash, cash equivalents and marketable securities $ 172,182 $ 172,202 $ 1 $ (21 )
Available-for-sale securities reported at fair value	Available-for-sale securities are reported at fair value on the balance sheets and classified as follows: As of June 30, December 31, (In thousands) Cash equivalents $ 116,080 $ 84,263 Short term marketable securities 746 36,888 Total cash equivalents and marketable securities 116,826 121,151 Cash 51,127 51,031 Total cash, cash equivalents and marketable securities $ 167,953 $ 172,182
Estimated fair value of cash equivalents and marketable securities classified by the length of time that the securities have been in a continuous unrealized loss position	The estimated fair value of cash equivalents and marketable securities classified by the length of time that the securities have been in a continuous unrealized loss position at June 30, 2017 and December 31, 2016 are as follows: Fair Value Gross Unrealized Loss June 30, December 31, June 30, December 31, (In thousands) Less than one year U.S. Government bonds and notes $ 8,997 $ 18,395 $ — $ — Corporate notes, bonds and commercial paper 33,668 54,377 (4 ) (21 ) Total Corporate notes, bonds, and commercial paper and U.S. Government bonds and notes $ 42,665 $ 72,772 $ (4 ) $ (21 )

Fair Value of Financial Instr25

Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Summary of the valuation of cash equivalents and marketable securities by pricing levels	The following table presents the financial instruments that are carried at fair value and summarizes the valuation of its cash equivalents and marketable securities by the above pricing levels as of June 30, 2017 and December 31, 2016 : As of June 30, 2017 Total Quoted Market Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In thousands) Money market funds $ 15,460 $ 15,460 $ — $ — U.S. Government bonds and notes 63,612 — 63,612 — Corporate notes, bonds, commercial paper and other 37,754 746 37,008 — Total available-for-sale securities $ 116,826 $ 16,206 $ 100,620 $ — As of December 31, 2016 Total Quoted Market Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In thousands) Money market funds $ 10,681 $ 10,681 $ — $ — U.S. Government bonds and notes 48,292 — 48,292 — Corporate notes, bonds, commercial paper and other 62,178 303 61,875 — Total available-for-sale securities $ 121,151 $ 10,984 $ 110,167 $ —
Financial instruments not carried at fair value but requiring fair value disclosure	The following table presents the financial instruments that are not carried at fair value but require fair value disclosure as of June 30, 2017 and December 31, 2016 : As of June 30, 2017 As of December 31, 2016 (In thousands) Face Value Carrying Value Fair Value Face Value Carrying Value Fair Value 1.125% Convertible Senior Notes due 2018 (the "2018 Notes") $ 138,000 $ 129,690 $ 151,386 $ 138,000 $ 126,167 $ 173,961

Convertible Notes (Tables)

Convertible Notes (Tables)	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
Schedule of convertible notes	The Company’s convertible notes are shown in the following table: (In thousands) As of June 30, 2017 As of December 31, 2016 1.125% Convertible Senior Notes due 2018 $ 138,000 $ 138,000 Unamortized discount (7,673 ) (10,913 ) Unamortized debt issuance costs (637 ) (920 ) Total convertible notes $ 129,690 $ 126,167 Less current portion — — Total long-term convertible notes $ 129,690 $ 126,167
Schedule of interest expense on notes	Interest expense related to the notes for the three and six months ended June 30, 2017 and 2016 was as follows: Three Months Ended Six Months Ended June 30, June 30, 2017 2016 2017 2016 (In thousands) 2018 Notes coupon interest at a rate of 1.125% $ 388 $ 388 776 776 2018 Notes amortization of discount and debt issuance costs at an additional effective interest rate of 5.5% 1,774 1,675 3,523 3,326 Total interest expense on convertible notes $ 2,162 $ 2,063 $ 4,299 $ 4,102

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Company's material contractual obligations	As of June 30, 2017 , the Company’s material contractual obligations were as follows (in thousands): Total Remainder of 2017 2018 2019 2020 2021 Thereafter Contractual obligations (1) Imputed financing obligation (2) $ 19,103 $ 3,185 $ 6,447 $ 6,602 $ 2,869 $ — $ — Leases and other contractual obligations 18,784 4,213 4,569 3,514 2,549 2,646 1,293 Software licenses (3) 18,557 4,849 10,176 3,532 — — — Convertible notes 138,000 — 138,000 — — — — Interest payments related to convertible notes 2,328 776 1,552 — — — — Total $ 196,772 $ 13,023 $ 160,744 $ 13,648 $ 5,418 $ 2,646 $ 1,293 _________________________________________ (1) The above table does not reflect possible payments in connection with uncertain tax benefits of approximately $22.9 million including $20.7 million recorded as a reduction of long-term deferred tax assets and $2.2 million in long-term income taxes payable as of June 30, 2017 . As noted below in Note 12, “Income Taxes,” although it is possible that some of the unrecognized tax benefits could be settled within the next 12 months, the Company cannot reasonably estimate the outcome at this time. (2) With respect to the imputed financing obligation, the main components of the difference between the amount reflected in the contractual obligations table and the amount reflected on the unaudited condensed consolidated balance sheets are the interest on the imputed financing obligation and the estimated common area expenses over the future periods. The amount includes the amended Ohio lease and the amended Sunnyvale lease. (3) The Company has commitments with various software vendors for non-cancellable agreements generally having terms longer than one year.

Equity Incentive Plans and St28

Equity Incentive Plans and Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares available for grant under stock-based incentive plans	A summary of shares available for grant under the Company’s plans is as follows: Shares Available for Grant Shares available as of December 31, 2016 7,305,368 Stock options granted (498,426 ) Stock options forfeited 1,472,366 Nonvested equity stock and stock units granted (1) (2) (3,553,590 ) Nonvested equity stock and stock units forfeited (1) 714,375 Total available for grant as of June 30, 2017 5,440,093 _________________________________________ (1) For purposes of determining the number of shares available for grant under the 2015 Plan against the maximum number of shares authorized, each share of restricted stock granted reduces the number of shares available for grant by 1.5 shares and each share of restricted stock forfeited increases shares available for grant by 1.5 shares. (2) Amount includes 266,847 shares that have been reserved for potential future issuance related to certain performance unit awards granted in the first quarter of 2017 and discussed under the section titled "Nonvested Equity Stock and Stock Units" below.
Schedule of stock option activity	The following table summarizes stock option activity under the 2006 Plan and 2015 Plan for the six months ended June 30, 2017 and information regarding stock options outstanding, exercisable, and vested and expected to vest as of June 30, 2017 . Options Outstanding Number of Shares Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term (years) Aggregate Intrinsic Value (In thousands, except per share amounts) Outstanding as of December 31, 2016 7,008,833 $ 9.34 Options granted 498,426 $ 12.74 Options exercised (654,388 ) $ 7.04 Options forfeited (1,472,366 ) $ 10.95 Outstanding as of June 30, 2017 5,380,505 $ 9.49 5.48 $ 16,061 Vested or expected to vest at June 30, 2017 5,297,443 $ 9.45 5.43 $ 16,037 Options exercisable at June 30, 2017 3,874,169 $ 9.20 4.58 $ 13,287
Weighted-average assumptions for Stock Option Plans	The following table presents the weighted-average assumptions used to estimate the fair value of stock options granted that contain only service conditions in the periods presented. Stock Option Plan Three Months Ended Six Months Ended June 30, June 30, 2017 2016 2017 2016 Stock Option Plan Expected stock price volatility 32 % — % 32 % 36 % Risk free interest rate 1.8 % — % 1.8% - 1.9% 1.7 % Expected term (in years) 5.3 — 5.3 - 5.4 6.1 Weighted-average fair value of stock options granted to employees $ 3.84 $ — $ 4.12 $ 4.66
Schedule of nonvested equity stock and stock units activity	The following table reflects the activity related to nonvested equity stock and stock units for the six months ended June 30, 2017 : Nonvested Equity Stock and Stock Units Shares Weighted- Average Grant-Date Fair Value Nonvested at December 31, 2016 4,863,056 $ 12.33 Granted 2,191,162 $ 12.81 Vested (615,671 ) $ 11.59 Forfeited (450,339 ) $ 12.54 Nonvested at June 30, 2017 5,988,208 $ 12.57
Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]	Employee Stock Purchase Plan Six Months Ended June 30, 2017 2016 Employee Stock Purchase Plan Expected stock price volatility 27 % 33 % Risk free interest rate 0.98 % 0.41 % Expected term (in years) 0.5 0.5 Weighted-average fair value of purchase rights granted under the purchase plan $ 2.87 $ 2.86

Recent Accounting Pronounceme29

Recent Accounting Pronouncements ASU 2016-09 (Details) $ in Millions	Mar. 31, 2017USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	$ 38.2

Earnings (Loss) Per Share (Deta

Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Numerator:
Net Income (Loss)	$ 2,605	$ 3,876	$ 5,611	$ 5,754
Denominator:
Weighted-average common shares outstanding, Basic (in shares)	110,060	109,904	110,758	109,818
Effect of potential dilutive common shares	2,505	2,157	3,333	2,384
Denominator:
Weighted-average common shares outstanding, Diluted (in shares)	112,565	112,061	114,091	112,202
Earnings Per Share, Basic	$ 0.02	$ 0.04	$ 0.05	$ 0.05
Earnings Per Share, Diluted	$ 0.02	$ 0.03	$ 0.05	$ 0.05

Earnings (Loss) Per Share (De31

Earnings (Loss) Per Share (Details 2) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Options
Anti-dilutive shares excluded from calculation of earnings per share
Anti-dilutive shares excluded from calculation of earnings per share	2	2.3	2	2.3

Intangible Asset and Goodwill

Intangible Asset and Goodwill (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2017USD ($)
Goodwill [Roll Forward]
Beginning Balance	$ 204,794
Additions to Goodwill	803
Impairment Charge of Goodwill	0
Ending Balance	207,959
Goodwill, Translation Adjustments	2,362
MID Segment
Goodwill [Roll Forward]
Beginning Balance	66,643
Additions to Goodwill	0
Impairment Charge of Goodwill	0
Ending Balance	66,643
Goodwill, Translation Adjustments	0
RSD Segment
Goodwill [Roll Forward]
Beginning Balance	138,151
Impairment Charge of Goodwill	0
Ending Balance	141,316
Goodwill, Translation Adjustments	2,362
Other
Goodwill [Roll Forward]
Ending Balance	0
Goodwill [Member] | RSD Segment
Goodwill [Roll Forward]
Additions to Goodwill	$ 803

Intangible Asset and Goodwill33

Intangible Asset and Goodwill (Details 2) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Goodwill
Gross Carrying Amount	$ 229,729
Accumulated Impairment Losses	(21,770)
Net Carrying Amount	207,959	$ 204,794
MID Segment
Goodwill
Gross Carrying Amount	66,643
Accumulated Impairment Losses	0
Net Carrying Amount	66,643	66,643
RSD Segment
Goodwill
Gross Carrying Amount	141,316
Accumulated Impairment Losses	0
Net Carrying Amount	141,316	$ 138,151
Other
Goodwill
Gross Carrying Amount	21,770
Accumulated Impairment Losses	(21,770)
Net Carrying Amount	$ 0

Intangible Asset and Goodwill34

Intangible Asset and Goodwill (Details 3) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Components of intangible assets
Accumulated Amortization	$ (218,672)		$ (218,672)		$ (194,777)
Intangible Assets, Gross (Excluding Goodwill)	330,547		330,547		327,165
Amortization expense for intangible assets	10,500	$ 8,200	20,938	$ 15,871
Intangible Assets, Net	111,875		111,875		132,388
Existing technology
Components of intangible assets
Gross Carrying Amount	257,911		257,911		256,656
Accumulated Amortization	(174,539)		(174,539)		(156,577)
Net Carrying Amount	83,372		$ 83,372		$ 100,079
Existing technology | Minimum [Member]
Components of intangible assets
Useful Life (in years)			3 years		3 years
Existing technology | Maximum [Member]
Components of intangible assets
Useful Life (in years)			10 years		10 years
Customer Contracts [Member]
Components of intangible assets
Gross Carrying Amount	67,236		$ 67,236		$ 65,109
Accumulated Amortization	(43,833)		(43,833)		(37,900)
Net Carrying Amount	23,403		$ 23,403		$ 27,209
Customer Contracts [Member] | Minimum [Member]
Components of intangible assets
Useful Life (in years)			1 year		1 year
Customer Contracts [Member] | Maximum [Member]
Components of intangible assets
Useful Life (in years)			10 years		10 years
Non-compete agreements
Components of intangible assets
Useful Life (in years)			3 years		3 years
Gross Carrying Amount	300		$ 300		$ 300
Accumulated Amortization	(300)		(300)		(300)
Net Carrying Amount	0		0		0
Favorable contracts
Components of intangible assets
Net Carrying Amount	2,200		2,200		3,600
Cash received related to favorable contracts	1,200	$ 2,400	2,400	$ 4,100
In Process Research and Development [Member]
Components of intangible assets
Indefinite-Lived Intangible Assets (Excluding Goodwill)	$ 5,100		$ 5,100		$ 5,100

Intangible Asset and Goodwill35

Intangible Asset and Goodwill (Details 4) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Estimated future amortization expense of intangible assets
2017 (remaining 6 months)	$ 22,174
2,018	29,338
2,019	19,594
2,020	18,876
2,021	12,500
Thereafter	9,393
Net Carrying Amount	$ 111,875	$ 132,388

Segments and Major Customers (D

Segments and Major Customers (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Financial information of business segments
Revenues	$ 94,720	$ 76,501	$ 192,071	$ 149,183
Segment operating expenses	44,669	33,426	86,058	64,505
Segment reconciling items	(41,807)	(31,067)	(84,335)	(63,376)
Operating income (loss)	8,244	12,008	21,678	21,302
Interest and other income (expense), net	(3,132)	(2,025)	(6,184)	(4,924)
Income (Loss) before income taxes	5,112	9,983	15,494	16,378
MID Segment
Financial information of business segments
Revenues	67,402	54,467	137,997	108,012
Segment operating expenses	23,801	13,229	44,056	25,272
Segment Operating Income (Loss)	43,601	41,238	93,941	82,740
RSD Segment
Financial information of business segments
Revenues	23,366	16,407	46,571	30,508
Segment operating expenses	12,214	13,105	24,613	25,015
Segment Operating Income (Loss)	11,152	3,302	21,958	5,493
Other
Financial information of business segments
Revenues	3,952	5,627	7,503	10,663
Segment operating expenses	8,654	7,092	17,389	14,218
Segment Operating Income (Loss)	(4,702)	(1,465)	(9,886)	(3,555)
Operating Segments [Member]
Financial information of business segments
Segment Operating Income (Loss)	$ 50,051	$ 43,075	$ 106,013	$ 84,678

Segments and Major Customers 37

Segments and Major Customers (Details 1) - Customer Concentration Risk - Accounts Receivable [Member]	Jun. 30, 2017	Dec. 31, 2016
Customer 1 [Member]
Concentration Risk [Line Items]
Customer concentration risk		17.00%
Customer 2 [Member]
Concentration Risk [Line Items]
Customer concentration risk		12.00%
Customer 3 [Member]
Concentration Risk [Line Items]
Customer concentration risk	20.00%	13.00%
Customer 4 [Member]
Concentration Risk [Line Items]
Customer concentration risk	25.00%

Segments and Major Customers 38

Segments and Major Customers (Details 2) - Customer Concentration Risk - Sales, net	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Customer A
Concentration Risk [Line Items]
Revenue from major customer as a percentage of total revenue	17.00%	20.00%	17.00%	21.00%
Customer B
Concentration Risk [Line Items]
Revenue from major customer as a percentage of total revenue	13.00%	21.00%	13.00%	21.00%
Customer C
Concentration Risk [Line Items]
Revenue from major customer as a percentage of total revenue	14.00%	13.00%	14.00%	13.00%

Segments and Major Customers 39

Segments and Major Customers (Details 3) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Major Customer Disclosure
Revenues	$ 94,720	$ 76,501	$ 192,071	$ 149,183
South Korea
Major Customer Disclosure
Revenues	28,291	31,632	57,260	63,086
USA
Major Customer Disclosure
Revenues	41,155	26,532	79,593	51,776
Japan
Major Customer Disclosure
Revenues	7,057	5,911	13,575	10,898
Europe
Major Customer Disclosure
Revenues	4,243	4,377	8,681	8,189
Canada
Major Customer Disclosure
Revenues	1,352	1,168	2,420	1,382
SINGAPORE
Major Customer Disclosure
Revenues	4,889	4,526	12,636	9,145
Asia-Other
Major Customer Disclosure
Revenues	$ 7,733	$ 2,355	$ 17,906	$ 4,707

Marketable Securities (Details)

Marketable Securities (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Cash equivalents and marketable securities
Maximum maturity period of available-for-sale securities (in years)	3 years	3 years
Maximum remaining maturity period of available-for-sale securities (in years)	1 year	1 year
Fair Value	$ 116,826	$ 121,151
Amortized Cost	116,828	121,171
Gross Unrealized Gains	2	1
Gross Unrealized Losses	(4)	(21)
Cash, fair value	51,127	51,031
Cash, amortized cost	51,127	51,031
Cash, cash equivalents and marketable securities
Fair Value	167,953	172,182
Amortized Cost	167,955	172,202
Gross Unrealized Gains	2	1
Gross Unrealized Losses	(4)	(21)
Money market funds
Cash equivalents and marketable securities
Fair Value	15,460	10,681
Amortized Cost	15,460	10,681
Gross Unrealized Gains	0	0
Gross Unrealized Losses	$ 0	$ 0
Weighted Rate of Return (as a percent)	0.83%	0.41%
US Treasury and Government Short-term Debt Securities [Member]
Cash equivalents and marketable securities
Fair Value	$ 63,612	$ 48,292
Amortized Cost	63,610	48,291
Gross Unrealized Gains	2	1
Gross Unrealized Losses	$ 0	$ 0
Weighted Rate of Return (as a percent)	0.83%	0.39%
Corporate notes, bonds and commercial paper
Cash equivalents and marketable securities
Fair Value	$ 37,754	$ 62,178
Amortized Cost	37,758	62,199
Gross Unrealized Gains	0	0
Gross Unrealized Losses	$ (4)	$ (21)
Weighted Rate of Return (as a percent)	0.97%	0.66%

Marketable Securities Marketabl

Marketable Securities Marketable Securities (Details 1) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	$ 116,826	$ 121,151
Cash, fair value	51,127	51,031
Cash, Cash Equivalents and Short Term Investments, Fair Value Disclosure	167,953	172,182
Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	116,080	84,263
Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	$ 746	$ 36,888

Marketable Securities (Details

Marketable Securities (Details 2) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Cash equivalents and marketable securities, Continuous unrealized loss position
Less than one year, Fair Value	$ 42,665	$ 72,772
Unrealized gain (loss), Gross
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(4)	(21)
US Treasury and Government Short-term Debt Securities [Member]
Cash equivalents and marketable securities, Continuous unrealized loss position
Less than one year, Fair Value	8,997	18,395
Unrealized gain (loss), Gross
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Corporate Debt Securities [Member]
Cash equivalents and marketable securities, Continuous unrealized loss position
Less than one year, Fair Value	33,668	54,377
Unrealized gain (loss), Gross
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (4)	$ (21)

Fair Value of Financial Instr43

Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	$ 116,826	$ 121,151
Money market funds
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	15,460	10,681
US Treasury and Government Short-term Debt Securities [Member]
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	63,612	48,292
Corporate notes, bonds and commercial paper
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	37,754	62,178
Recurring basis
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	116,826	121,151
Recurring basis | Money market funds
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	15,460	10,681
Recurring basis | US Treasury and Government Short-term Debt Securities [Member]
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	63,612	48,292
Recurring basis | Corporate notes, bonds and commercial paper
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	37,754	62,178
Recurring basis | Quoted Market Prices in Active Markets (Level 1)
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	16,206	10,984
Recurring basis | Quoted Market Prices in Active Markets (Level 1) | Money market funds
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	15,460	10,681
Recurring basis | Quoted Market Prices in Active Markets (Level 1) | US Treasury and Government Short-term Debt Securities [Member]
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	0	0
Recurring basis | Quoted Market Prices in Active Markets (Level 1) | Corporate notes, bonds and commercial paper
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	746	303
Recurring basis | Significant Other Observable Inputs (Level 2)
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	100,620	110,167
Recurring basis | Significant Other Observable Inputs (Level 2) | Money market funds
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	0	0
Recurring basis | Significant Other Observable Inputs (Level 2) | US Treasury and Government Short-term Debt Securities [Member]
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	63,612	48,292
Recurring basis | Significant Other Observable Inputs (Level 2) | Corporate notes, bonds and commercial paper
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	37,008	61,875
Recurring basis | Significant Unobservable Inputs (Level 3)
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Money market funds
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | US Treasury and Government Short-term Debt Securities [Member]
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Corporate notes, bonds and commercial paper
Financial assets subject to fair value measurements and the necessary disclosures
Total available-for-sale securities	$ 0	$ 0

Fair Value of Financial Instr44

Fair Value of Financial Instruments (Details 2) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Convertible Senior Notes
Debt Instrument [Line Items]
Convertible Notes Payable	$ 129,690	$ 126,167
1.125% Convertible Senior Notes due 2018
Debt Instrument [Line Items]
Debt Instrument, Face Amount	138,000
1.125% Convertible Senior Notes due 2018 | Convertible Senior Notes
Debt Instrument [Line Items]
Debt Instrument, Face Amount	138,000	138,000
Convertible Notes Payable	129,690	126,167
Convertible Debt, Fair Value Disclosures	$ 151,386	$ 173,961
Convertible notes stated interest rate (as a percent)	1.125%	1.125%

Convertible Notes (Details)

Convertible Notes (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Convertible notes, long-term	$ 129,690	$ 126,167
1.125% Convertible Senior Notes due 2018
Debt Instrument [Line Items]
Principal amount of convertible notes	138,000
Convertible Senior Notes
Debt Instrument [Line Items]
Total convertible notes	129,690	126,167
Convertible notes, short-term	0	0
Convertible notes, long-term	$ 129,690	$ 126,167
Convertible Senior Notes | 1.125% Convertible Senior Notes due 2018
Debt Instrument [Line Items]
Convertible notes stated interest rate (as a percent)	1.125%	1.125%
Principal amount of convertible notes	$ 138,000	$ 138,000
Unamortized discount	(7,673)	(10,913)
Unamortized Debt Issuance Expense	(637)	(920)
Total convertible notes	$ 129,690	$ 126,167

Convertible Notes (Details 3)

Convertible Notes (Details 3) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Interest expense related to notes
Amortization of discount and debt issuance costs			$ 3,523	$ 3,326
Interest expense	$ 3,261	$ 3,163	6,467	6,304
Convertible Senior Notes
Interest expense related to notes
Interest expense	2,162	2,063	4,299	4,102
Convertible Senior Notes | 1.125% Convertible Senior Notes due 2018
Interest expense related to notes
Interest	388	388	776	776
Amortization of discount and debt issuance costs	$ 1,774	$ 1,675	$ 3,523	$ 3,326
Convertible notes stated interest rate (as a percent)	1.125%		1.125%		1.125%
Debt Instrument, Interest Rate, Effective Percentage	5.50%	5.50%	5.50%	5.50%

Commitments and Contingencies47

Commitments and Contingencies (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Contractual obligations
Remainder of 2017	[1]	$ 13,023		$ 13,023
2,018	[1]	160,744		160,744
2,019	[1]	13,648		13,648
2,020	[1]	5,418		5,418
2,021	[1]	2,646		2,646
Contractual Obligation, Payments Due after Fourth Full Fiscal Year	[1]	1,293		1,293
Contractual Obligation	[1]	196,772		196,772
Unrecognized tax benefits		22,900		22,900		$ 21,900
Unrecognized tax benefits, reduction of long-term deferred tax assets		20,700		20,700		19,700
Unrecognized tax benefits included in long-term income taxes payable		2,200		$ 2,200		2,200
Terms of noncancellable license agreement, minimum (in years)				1 year
Rent expense		1,100	$ 900	$ 2,100	$ 1,700
Deferred Rent Credit, Current		300		300		$ 500
Imputed financing obligation
Contractual obligations
Remainder of 2017	[1],[2]	3,185		3,185
2,018	[1],[2]	6,447		6,447
2,019	[1],[2]	6,602		6,602
2,020	[1],[2]	2,869		2,869
2,021	[1],[2]	0		0
Contractual Obligation, Payments Due after Fourth Full Fiscal Year	[1],[2]	0		0
Contractual Obligation	[1],[2]	19,103		19,103
Leases and other contractual obligations
Contractual obligations
Remainder of 2017	[1]	4,213		4,213
2,018	[1]	4,569		4,569
2,019	[1]	3,514		3,514
2,020	[1]	2,549		2,549
2,021	[1]	2,646		2,646
Contractual Obligation, Payments Due after Fourth Full Fiscal Year	[1]	1,293		1,293
Contractual Obligation	[1]	18,784		18,784
Software licenses
Contractual obligations
Remainder of 2017	[1],[3]	4,849		4,849
2,018	[1],[3]	10,176		10,176
2,019	[1],[3]	3,532		3,532
2,020	[1],[3]	0		0
2,021	[1],[3]	0		0
Contractual Obligation, Payments Due after Fourth Full Fiscal Year	[1],[3]	0		0
Contractual Obligation	[1],[3]	18,557		18,557
Convertible notes
Contractual obligations
Remainder of 2017	[1]	0		0
2,018	[1]	138,000		138,000
2,019	[1]	0		0
2,020	[1]	0		0
2,021	[1]	0		0
Contractual Obligation, Payments Due after Fourth Full Fiscal Year	[1]	0		0
Contractual Obligation	[1]	138,000		138,000
Interest payments related to convertible notes
Contractual obligations
Remainder of 2017	[1]	776		776
2,018	[1]	1,552		1,552
2,019	[1]	0		0
2,020	[1]	0		0
2,021	[1]	0		0
Contractual Obligation, Payments Due after Fourth Full Fiscal Year	[1]	0		0
Contractual Obligation	[1]	$ 2,328		$ 2,328
[1]	The above table does not reflect possible payments in connection with uncertain tax benefits of approximately $22.9 million including $20.7 million recorded as a reduction of long-term deferred tax assets and $2.2 million in long-term income taxes payable as of June 30, 2017. As noted below in Note 12, “Income Taxes,” although it is possible that some of the unrecognized tax benefits could be settled within the next 12 months, the Company cannot reasonably estimate the outcome at this time.
[2]	With respect to the imputed financing obligation, the main components of the difference between the amount reflected in the contractual obligations table and the amount reflected on the unaudited condensed consolidated balance sheets are the interest on the imputed financing obligation and the estimated common area expenses over the future periods. The amount includes the amended Ohio lease and the amended Sunnyvale lease.
[3]	The Company has commitments with various software vendors for non-cancellable agreements generally having terms longer than one year.

Equity Incentive Plans and St48

Equity Incentive Plans and Stock-Based Compensation (Details Textual) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Apr. 23, 2015
Stock-Based Compensation
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	$ 0.2		$ 0.5
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	0.00%
Minimum [Member]
Stock-Based Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			0.00%
Maximum [Member]
Stock-Based Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			150.00%
Stock Compensation Plan [Member]
Stock-Based Compensation
Shares available for issuance	5,440,093		5,440,093		7,305,368
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	35,400,000		35,400,000			4,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures			498,426
Employee Stock Option [Member]
Stock-Based Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	5,380,505		5,380,505		7,008,833
Entity Closing Stock Price	$ 11.43		$ 11.43
Share Based Compensation Arrangement by Share Based Payment Award Options, In The Money Outstanding, Number	3,703,530		3,703,530
Share Based Compensation Arrangement By Share Based Payment Award, Options in the Money Exercisable, Number	3,063,509		3,063,509
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures	40,000		498,426	440,000
Share Based Compensation Arrangement by Share Based Payment Award Options, Grants in Period, Total Fair Value	$ 0.2		$ 2.1	$ 2.1
Stock-based compensation	0.7	$ 1.1	1.4	2.3
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	4.9		$ 4.9
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition			2 years 7 days
Total fair value of options vested	20.7		$ 20.7
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$ 1.8	0.9	3.8	4
Proceeds from Stock Options Exercised			$ 4.6
Employee Stock [Member]
Stock-Based Compensation
Shares available for issuance	1,089,649		1,089,649
Share Based Compensation Arrangement by Share Based Payment Award Discount from Market Price Specific Date			15.00%
Stock-based compensation	$ 0.4	$ 0.3	$ 0.9	$ 0.8
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 0.5		$ 0.5
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	4 months
Stock Issued During Period, Shares, Employee Stock Purchase Plans			361,994	340,349
Employee Stock Purchase Plans Price Per Share			$ 10.33	$ 8.96
Restricted Stock and Stock Units [Member]
Stock-Based Compensation
Granted (in shares)	151,354	184,456	2,191,162	2,024,640
Stock-based compensation	$ 5.5	$ 3.7	$ 10.8	$ 6.8
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 48.9		$ 48.9
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years 8 months 23 days
Share Based Compensation Arrangement by Share Based Payment Award Equity Instruments Other than Options Nonvested Requisite Service Period			4 years
Share Based Compensation Arrangement by Share Based Payment Award Equity Instruments Other than Options Nonvested Grants in Period Total Fair Value	$ 1.9	2.3	$ 28.1	25
Stock Options with Market Condition [Member] | Employee Stock Option [Member]
Stock-Based Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	320,000		320,000		1,135,000
Performance Shares [Member] | Restricted Stock and Stock Units [Member]
Stock-Based Compensation
Stock-based compensation	$ 1	$ 0.7	$ 1.9	$ 1.3
Director [Member] | Restricted Stock and Stock Units [Member]
Stock-Based Compensation
Share Based Compensation Arrangement by Share Based Payment Award Equity Instruments Other than Options Nonvested Requisite Service Period			1 year

Equity Incentive Plans and St49

Equity Incentive Plans and Stock-Based Compensation (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Apr. 23, 2015
Employee Stock [Member]
Stock-Based Compensation
Stock-based compensation		$ 0.4	$ 0.3	$ 0.9	$ 0.8
Shares available for grant
Shares available, at the end of the period		1,089,649		1,089,649
Stock-Based Incentive Compensation Plans
Stock-Based Compensation
Number of shares reserved under the Plans		35,400,000		35,400,000		4,000,000
Shares available for grant
Shares available, at the beginning of the year				7,305,368
Stock options granted (in shares)				(498,426)
Stock options forfeited (in shares)				1,472,366
Nonvested equity stock and stock units granted (in shares)	[1],[2]			(3,553,590)
Nonvested equity stock and stock units forfeited (in shares)	[2]			714,375
Shares available, at the end of the period		5,440,093		5,440,093
Conversion factor used to calculate the decrease in the number of shares available for grant resulting from the grant of restricted stock awards		1.5		1.5
Conversion factor used to calculate the increase in the number of shares available for grant resulting from the forfeiture of restricted stock awards		1.5		1.5
Restricted Stock and Stock Units [Member]
Stock-Based Compensation
Stock-based compensation		$ 5.5	3.7	$ 10.8	6.8
Potential Additional Performance Stock Units [Domain]
Shares available for grant
Nonvested equity stock and stock units granted (in shares)	[1],[2]			266,847
Performance Shares [Member] | Restricted Stock and Stock Units [Member]
Stock-Based Compensation
Stock-based compensation		$ 1	$ 0.7	$ 1.9	$ 1.3
[1]	(2)Amount includes 266,847 shares that have been reserved for potential future issuance related to certain performance unit awards granted in the first quarter of 2017 and discussed under the section titled "Nonvested Equity Stock and Stock Units" below.
[2]	For purposes of determining the number of shares available for grant under the 2015 Plan against the maximum number of shares authorized, each share of restricted stock granted reduces the number of shares available for grant by 1.5 shares and each share of restricted stock forfeited increases shares available for grant by 1.5 shares.

Equity Incentive Plans and St50

Equity Incentive Plans and Stock-Based Compensation (Details 2) - Employee Stock Option [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017	Jun. 30, 2016
Number of Shares
Outstanding, at the beginning of the period (in shares)		7,008,833
Options granted (in shares)	40,000	498,426	440,000
Options exercised (in shares)		(654,388)
Options forfeited (in shares)		(1,472,366)
Outstanding, at the end of the period (in shares)	5,380,505	5,380,505
Vested or expected to vest at the end of the period (in shares)	5,297,443	5,297,443
Options exercisable at the end of the period (in shares)	3,874,169	3,874,169
Weighted Average Exercise Price
Outstanding at the beginning of the year (in dollars per shares)		$ 9.34
Options granted (in dollars per share)		12.74
Options exercised (in dollars per share)		7.04
Options forfeited (in dollars per share)		10.95
Outstanding at the end of the period (in dollars per shares)	$ 9.49	9.49
Vested or expected to vest at the end of the period (in dollars per share)	9.45	9.45
Options exercisable at the end of the period (in dollars per share)	$ 9.20	$ 9.20
Weighted Average Remaining Contractual Term
Outstanding		5 years 5 months 23 days
Vested or expected to vest		5 years 5 months 5 days
Options exercisable		4 years 6 months 29 days
Aggregate Intrinsic Value
Outstanding	$ 16,061	$ 16,061
Vested or expected to vest	16,037	16,037
Options exercisable	$ 13,287	$ 13,287
Stock Options with Market Condition [Member]
Number of Shares
Outstanding, at the beginning of the period (in shares)		1,135,000
Outstanding, at the end of the period (in shares)	320,000	320,000

Equity Incentive Plans and St51

Equity Incentive Plans and Stock-Based Compensation (Details 3) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Employee Stock Option [Member]
Stock-Based Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures	40,000		498,426	440,000
Share Based Compensation Arrangement by Share Based Payment Award Options, Grants in Period, Total Fair Value	$ 0.2		$ 2.1	$ 2.1
Valuation assumptions
Expected stock price volatility (as a percent)	32.00%		32.00%	36.00%
Risk free interest rate	1.80%			1.70%
Expected term	5 years 4 months 6 days			6 years 29 days
Weighted-average fair value of stock options granted (in dollars per share)	$ 3.84		$ 4.12	$ 4.66
Weighted-Average Grant-Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum			1.80%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum			1.90%
Employee Stock Purchase Plan
Valuation assumptions
Expected stock price volatility (as a percent)			27.00%	33.00%
Risk free interest rate			0.98%	0.41%
Expected term			6 months	6 months
Weighted-average fair value of stock options granted (in dollars per share)			$ 2.87	$ 2.86
Restricted Stock and Stock Units [Member]
Nonvested equity stock and stock units
Nonvested at the beginning of the period (in shares)			4,863,056
Granted (in shares)	151,354	184,456	2,191,162	2,024,640
Vested (in shares)			(615,671)
Forfeited (in shares)			(450,339)
Nonvested at the end of the period (in shares)	5,988,208		5,988,208
Weighted-Average Grant-Date Fair Value
Nonvested at the beginning of the period (in dollars per share)			$ 12.33
Granted (in dollars per share)			12.81
Vested (in dollars per share)			11.59
Forfeited (in dollars per share)			12.54
Nonvested at the end of the period (in dollars per share)	$ 12.57		$ 12.57
Minimum [Member] | Employee Stock Option [Member]
Valuation assumptions
Expected term			5 years 4 months 6 days
Maximum [Member] | Employee Stock Option [Member]
Valuation assumptions
Expected term			5 years 4 months 21 days

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2017	Jan. 21, 2015
Share repurchase program
Stock Repurchase Program, Number of Shares Authorized to be Repurchased		20,000,000
UpfrontPaymentUnderAcceleratedStockRepurchaseProgram	$ 50,000
Stock Repurchased and Retired During Period, Shares	3,187,000
Stock Repurchased and Retired During Period, Value	$ 40,000
UnsettledForwardContractIndexedtoIssuersStockClassifiedwithinStock	$ 10,000
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	8,300,000
Retained Earnings [Member]
Share repurchase program
Stock Repurchased and Retired During Period, Value	$ 29,400

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Valuation Allowance [Line Items]
Deferred Tax Assets, Gross	$ 219,500		$ 219,500
Deferred Tax Assets, Valuation Allowance	26,200		26,200
Provision for (benefit from) income taxes	2,507	$ 6,107	9,883	$ 10,624
Unrecognized tax benefits	22,900		22,900		$ 21,900
Portion of unrecognized tax benefits, which if recognized, would be recorded as an income tax benefit	2,200		2,200
Unrecognized tax benefits included in long-term income taxes payable	2,200		2,200		2,200
Unrecognized tax benefits, reduction of long-term deferred tax assets	20,700		20,700		$ 19,700
Foreign Tax Authority [Member]
Valuation Allowance [Line Items]
Income Taxes Paid	$ 5,400	$ 5,400	$ 10,900	$ 10,900