Entropic Communications 10-Q 5 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 31, 2013
Entity Information [Line Items]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'ENTR	'
Entity Registrant Name	'ENTROPIC COMMUNICATIONS INC	'
Entity Central Index Key	'0001227930	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	91,258,822

Unaudited_Condensed_Consolidat

Unaudited Condensed Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$27,901	$17,206	[1]
Marketable securities	59,549	79,981	[1]
Accounts receivable	40,797	41,847	[1]
Inventory	15,116	26,395	[1]
Deferred tax assets, current	13	7,157	[1]
Prepaid expenses and other current assets	17,405	11,988	[1]
Total current assets	160,781	184,574	[1]
Property and equipment, net	17,928	17,629	[1]
Long-term marketable securities	73,894	71,748	[1]
Intangible assets, net	50,487	46,997	[1]
Goodwill	4,688	4,664	[1]
Deferred tax assets, long-term	0	19,255	[1]
Other long-term assets	6,356	8,683	[1]
Total assets	314,134	353,550	[1]
Current liabilities:	'	'
Accounts payable	14,956	11,380	[1]
Accrued expenses and other current liabilities	7,158	8,067	[1]
Accrued payroll and benefits	8,156	9,474	[1]
Total current liabilities	30,270	28,921	[1]
Deferred rent	2,178	683	[1]
Other long-term liabilities	1,586	1,281	[1]
Stockholders’ equity:	'	'
Common stock	91	89	[1]
Additional paid-in capital	480,109	468,526	[1]
Accumulated deficit	-200,371	-146,119	[1]
Accumulated other comprehensive income	271	169	[1]
Total stockholders’ equity	280,100	322,665	[1]
Total liabilities and stockholders’ equity	$314,134	$353,550	[1]
[1]	(1) The unaudited condensed consolidated balance sheet at December 31, 2012 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

Unaudited_Condensed_Consolidat1

Unaudited Condensed Consolidated Statements of Operations (USD $)	3 Months Ended		9 Months Ended
Share data in Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net revenues	$56,376,000	$89,825,000	$201,445,000	$231,980,000
Cost of net revenues	28,863,000	45,778,000	104,837,000	111,886,000
Gross profit	27,513,000	44,047,000	96,608,000	120,094,000
Operating expenses:	'	'	'	'
Research and development	28,510,000	28,072,000	84,914,000	69,214,000
Sales and marketing	6,137,000	6,966,000	18,609,000	18,986,000
General and administrative	5,751,000	5,718,000	17,290,000	19,592,000
Amortization of intangibles	443,000	930,000	1,868,000	1,645,000
Restructuring charges	-69,000	0	1,694,000	0
Total operating expenses	40,772,000	41,686,000	124,375,000	109,437,000
Income (loss) from operations	-13,259,000	2,361,000	-27,767,000	10,657,000
Loss related to equity method investment	0	-799,000	-1,115,000	-2,536,000
Impairment of investment	0	0	-4,780,000	0
Other income, net	464,000	31,000	1,147,000	567,000
Income (loss) before income taxes	-12,795,000	1,593,000	-32,515,000	8,688,000
Income tax (benefit) provision	-860,000	1,185,000	21,737,000	4,214,000
Net (loss) income	($11,935,000)	$408,000	($54,252,000)	$4,474,000
Net (loss) income per share—basic (in dollars per share)	($0.13)	$0	($0.60)	$0.05
Net (loss) income per share—diluted (in dollars per share)	($0.13)	$0	($0.60)	$0.05
Weighted average number of shares used to compute net (loss) income per share—basic	91,069	88,399	90,225	87,913
Weighted average number of shares used to compute net (loss) income per share—diluted	91,069	90,885	90,225	89,918

Unaudited_Condensed_Consolidat2

Unaudited Condensed Consolidated Statements of Comprehensive (Loss) Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net (loss) income	($11,935)	$408	($54,252)	$4,474
Other comprehensive (loss) income, net of taxes:	'	'	'	'
Change in foreign currency translation adjustment	162	59	183	76
Available-for-sale investments:	'	'	'	'
Change in net unrealized gain/loss	159	172	-81	307
Other comprehensive (loss) income	321	231	102	383
Comprehensive (loss) income	($11,614)	$639	($54,150)	$4,857

Unaudited_Condensed_Consolidat3

Unaudited Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012
Operating activities:	'		'
Net (loss) income	($54,252,000)		$4,474,000
Adjustments to reconcile net (loss) income to net cash provided by operating activities:	'		'
Depreciation and amortization	6,288,000		3,937,000
Amortization of intangible assets	8,750,000		5,447,000
Change in acquisition related contingent consideration liability	131,000		-230,000
Deferred taxes	24,221,000		-202,000
Excess tax expense (benefit) on stock option exercises	2,177,000		-286,000
Stock-based compensation	11,821,000		10,982,000
Amortization of premiums on investments	2,593,000		2,652,000
Provision for excess and obsolete inventory	3,492,000		365,000
Loss related to equity method investment	1,115,000		2,536,000
Impairment of investment	4,780,000		0
Gain on disposal of assets	-98,000		0
Changes in operating assets and liabilities:	'		'
Accounts receivable	1,050,000		-2,142,000
Inventory	7,787,000		-12,553,000
Prepaid expenses and other current assets	-5,400,000		-4,117,000
Other long-term assets	-3,586,000		-363,000
Accounts payable	3,580,000		8,524,000
Accrued expenses and other current liabilities	30,000		3,296,000
Accrued payroll and benefits	-1,251,000		6,728,000
Deferred rent	1,497,000		-371,000
Other long-term liabilities	305,000		942,000
Net cash provided by operating activities	14,768,000		30,079,000
Investing activities:	'		'
Purchases of property and equipment	-6,482,000		-4,876,000
Purchases of marketable securities	-93,364,000		-79,719,000
Sales/maturities of marketable securities	108,962,000		129,953,000
Net cash used in investing activities	-3,901,000		-31,006,000
Financing activities:	'		'
Net proceeds from the issuance of equity plan exercises	1,941,000		2,885,000
Excess tax (expense) benefit on stock option exercises	-2,177,000		286,000
Net cash (used in) provided by financing activities	-236,000		3,171,000
Net effect of exchange rates on cash	64,000		74,000
Net increase in cash and cash equivalents	10,695,000		2,318,000
Cash and cash equivalents at beginning of period	17,206,000	[1]	20,193,000
Cash and cash equivalents at end of period	27,901,000		22,511,000
Supplemental disclosure of cash flow information:	'		'
Cash paid for income taxes	726,000		4,475,000
STB Business [Member]	'		'
Investing activities:	'		'
Net cash used in acquisition	0		-69,490,000
PLX Technology, Inc., [Member]	'		'
Investing activities:	'		'
Net cash used in acquisition	0		-6,874,000
Mobius [Member]	'		'
Investing activities:	'		'
Net cash used in acquisition	($13,017,000)		$0
[1]	(1) The unaudited condensed consolidated balance sheet at December 31, 2012 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

Organization_and_Summary_of_Si

Organization and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Organization and Summary of Significant Accounting Policies	'
	Organization and Summary of Significant Accounting Policies
	Business
	Entropic Communications, Inc. was organized under the laws of the state of Delaware on January 31, 2001. Entropic Communications is a leading fabless semiconductor company that designs, develops and markets semiconductor solutions to enable home entertainment. Our technologies change the way traditional broadcast video, streaming video, and other multimedia content such as movies, music, games and photos are brought into, distributed and processed throughout the home.
	Basis of Presentation
	The accompanying interim unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles, or GAAP.
	The accompanying unaudited condensed consolidated financial statements include our accounts and those of our wholly-owned subsidiaries. All inter-company accounts and transactions have been eliminated in consolidation.
	The accompanying unaudited condensed consolidated financial statements include all adjustments, consisting of normal recurring accruals, which we consider necessary for a fair presentation of the financial position and results of operations for the periods presented.
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the unaudited condensed consolidated financial statements and these accompanying notes. Among the significant estimates affecting the unaudited condensed consolidated financial statements are those related to business combinations, allowance for doubtful accounts, inventory reserves, long-lived assets (including intangible assets), warranty reserves, accrued bonuses, income taxes, valuation of equity securities and stock-based compensation. On an ongoing basis, management reviews its estimates based upon currently available information. Actual results could differ materially from those estimates.
	Foreign Currency Translation
	The functional currency for our foreign subsidiaries is the local currency. Assets and liabilities denominated in foreign currencies are translated using the exchange rates on the balance sheet dates. Net revenues and expenses are translated using the average exchange rates prevailing during the year. Any translation adjustments resulting from this process are shown as a component of accumulated other comprehensive income within stockholders' equity in the unaudited condensed consolidated balance sheets. Foreign currency transaction gains and losses are reported in operating expenses in the unaudited condensed consolidated statements of operations.
	Derivative Financial Instruments
	Our primary objective for holding derivative financial instruments is to hedge non-functional currency risks and to guarantee a minimum fixed price in local currency. Our accounting policies for derivative financial instruments are based on the criteria for designation of a hedging transaction as an accounting hedge, either as a cash flow or fair value hedge. A cash flow hedge refers to the hedge of the exposure to variability in the cash flows of an asset or a liability, or of a forecasted transaction. A fair value hedge refers to the hedge of the exposure to changes in fair value of an asset or a liability, or of an unrecognized firm commitment. The criteria for designating a derivative as a hedge include the instrument's effectiveness in risk reduction and, in most cases, a one-to-one matching of the derivative instrument to its underlying transaction. Gains and losses from derivatives designated as fair value accounting hedges generally offset changes in the values of the hedged assets or liabilities over the life of the hedge. We recognize gains and losses on derivatives that are not currently designated as hedges for accounting purposes in earnings in other income, net. As of September 30, 2013, we had no derivative instruments designated as accounting hedges. As such, all gains and losses on derivatives for the three and nine months ended September 30, 2013 were recognized in earnings.
	Revenue Recognition
	Our net revenues are generated principally by sales of our semiconductor solutions products. During the three and nine months ended September 30, 2013 and 2012, product net revenues represented more than 99% of our total net revenues.
	We recognize product revenues when the following fundamental criteria are met: (i) persuasive evidence of an arrangement exists, (ii) delivery has occurred or services have been rendered, (iii) the price to the customer is fixed or determinable and (iv) collection of the resulting receivable is reasonably assured. These criteria are usually met at the time of product shipment; however, we do not recognize revenue until all substantive customer acceptance requirements have been met, when applicable.
	A portion of our sales are made through distributors, agents or customers acting as agents under agreements allowing for rights of return or other potential concessions. Net revenues on sales made through these distributors are not recognized until the distributors ship the product to their customers.
	Revenues derived from billing customers for shipping and handling costs are classified as a component of net revenues. Costs of shipping and handling charged by suppliers are classified as a component of cost of net revenues.
	We record reductions to net revenues for estimated product returns and pricing adjustments, such as competitive pricing programs, in the same period that the related revenue is recorded. The amount of these reductions is based on historical sales returns and historical participation in pricing programs and other factors known at the time. If actual returns or actual participation in pricing programs differ significantly from our estimates, such differences would be recorded in our results of operations for the period in which the actual returns become known or pricing programs terminate. To date, changes in estimated returns have not been material to net revenues in any related period.
	We are party to an inventory “hubbing” agreement with Motorola Mobility, Inc. (formerly Motorola, Inc.), or Motorola. Pursuant to this agreement, we deliver products to the designated third-party warehouse based upon Motorola's projected needs, but do not recognize product revenue unless and until Motorola removes our products from the third-party warehouse to incorporate into its own products.
	We have entered into agreements to license certain hardware and software, also referred to as the “nodes,” to certain members of the Multimedia over Coax Alliance, or MoCA, for a period of three years and to provide upgrades when and if they become available. The agreements limit the rights to use the nodes to test compliance of the members' own products to the MoCA specification. For these arrangements, we defer all of the license revenues when the nodes are delivered and recognize the revenues on a straight-line basis over the three-year term of the agreement. To date, revenues under these arrangements have not been material.
	We provide rebates on our products to certain customers. At the time of the sale, we accrue 100% of the potential rebate as a reduction to net revenue and, based on our historical experience rate, do not apply a breakage factor. The amount of these reductions is based upon the terms included in various rebate agreements. We reverse the accrual for unclaimed rebate amounts as specific rebate programs contractually end or when we believe unclaimed rebates are no longer subject to payment and will not be paid. For the three months ended September 30, 2013 and 2012 and the nine months ended September 30, 2013 and 2012, we reduced net revenue by $1.3 million, $0.2 million, $1.9 million and $0.4 million, respectively, in connection with our rebate programs.
	Concentration of Credit Risk
	Financial instruments that potentially subject us to concentration of credit risk consist primarily of cash and cash equivalents, marketable securities, accounts receivable and leases payable. Our policy is to place our cash, cash equivalents and marketable securities with high quality financial institutions in order to limit our credit exposure. We extend credit to certain of our customers based on an evaluation of the customer's financial condition and a cash deposit is generally not required. We estimate potential losses on trade receivables on an ongoing basis.
	We maintain cash and cash equivalent accounts with Federal Deposit Insurance Corporation, or FDIC, insured financial institutions. In addition, certain of the our interest bearing collateral money market and savings accounts are each insured up to $250,000 by the FDIC. Our exposure for amounts in excess of FDIC insured limits at September 30, 2013 was $20.6 million. We have not experienced any losses in such accounts.
	We invest cash in deposits and money market funds with major financial institutions, U.S. government obligations and debt securities of corporations with investment grade credit ratings in a variety of industries. It is our policy to invest in instruments that have a final maturity of no longer than two years, and to maintain a portfolio weighted average maturity of no longer than 12 months.
	Concentration of Supplier Risk
	We are dependent on NXP Semiconductors Netherlands B.V., or NXP, as our sole source manufacturer for some of our set-top-box, or STB, system-on-a-chip, or SoC, products and certain other products. If NXP became unable to manufacture these products for us in a timely manner and we were unable to find alternative vendors, our business, operating results and financial condition could be materially adversely affected. We are currently transitioning the manufacturing of certain STB SoC products to our other third-party manufacturers.
	Cash and Cash Equivalents
	Cash and cash equivalents consist of cash, money market funds and commercial paper. We consider all highly liquid investments with a maturity of three months or less from the date of purchase that are readily convertible into cash to be cash equivalents.
	Deferred Compensation
	In June 2011, we implemented a non-qualified deferred compensation plan that permits certain key employees to defer portions of their compensation, subject to annual deferral limits, and have it credited to one or more investment options in the plan. At September 30, 2013, we had marketable securities totaling $0.4 million related to investments in equity securities that are held in a rabbi trust under our non-qualified deferred compensation plan. The total related deferred compensation liability was $0.4 million at September 30, 2013, all of which was classified as non-current liabilities and is recorded in the unaudited condensed consolidated balance sheets under other long-term liabilities.
	Marketable Securities
	We account for marketable securities by determining the appropriate classification of such securities at the time of purchase and reevaluating such classification as of each balance sheet date. As of September 30, 2013, we had classified $0.5 million of bank and time deposits and $0.4 million held under our non-qualified deferred compensation plan as trading securities. Trading securities are bought and held principally for the purpose of selling in the near term and are reported at fair value, with unrealized gains and losses included in earnings. All other marketable securities were classified as available-for-sale. Cash equivalents and available-for-sale marketable securities are reported at fair value with the related unrealized gains and losses included in accumulated other comprehensive income, a component of stockholders' equity, net of tax. The investments are adjusted for amortization of premiums and discounts to maturity and such amortization is included in interest income. Realized gains and losses and declines in value judged to be other than temporary are determined based on the specific identification method and are reported in the unaudited condensed consolidated statements of operations.
	Fair Value of Financial Instruments
	The carrying amounts of cash equivalents, marketable securities, trade receivables, accounts payable and other accrued liabilities approximate fair value due to their relative short-term maturities. The fair value of marketable securities was determined using the quoted market price for those securities. The carrying amounts of our capital lease obligations and other long-term liabilities approximate their fair value. The fair value of capital lease obligations was estimated based on the current interest rates available to us for debt instruments with similar terms, degrees of risk and remaining maturities.
	Allowance for Doubtful Accounts
	We evaluate the collectability of accounts receivable based on a combination of factors. In cases where we are aware of circumstances that may impair a specific customer's ability to meet its financial obligations subsequent to the original sale, we will record a specific allowance against amounts due, and thereby reduce the net recognized receivable to the amount we reasonably believe will be collected. For all other customers, we recognize allowances for doubtful accounts based upon specific identification, industry and geographic concentrations, the current business environment and our historical experience. We recorded no allowance for doubtful accounts as of September 30, 2013 and December 31, 2012.
	Inventories
	Inventories are stated at the lower of cost (first-in, first-out) or market. Lower of cost or market adjustments reduce the carrying value of the related inventory and take into consideration reductions in sales prices, excess inventory levels and obsolete inventory. These adjustments are calculated on a part-by-part basis and, in general, represent excess inventory value on hand compared to 12-month demand projections. Once established, these adjustments are considered permanent and are not reversed until the related inventory is sold or disposed.
	We make estimates about future customer demand for our products when establishing the appropriate reserve for excess and obsolete inventory. We write down inventory that has become obsolete or unmarketable by an amount equal to the difference between the cost of inventory and the estimated market value based on assumptions about future demand and market conditions. Inventory write downs are a component of our product cost of goods sold. For the three months ended September 30, 2013 and 2012 and the nine months ended September 30, 2013 and 2012, we recorded charges for excess and obsolete inventory of $2.6 million, $8,000, $3.5 million and $0.4 million, respectively.
	Property and Equipment
	Property and equipment are stated at cost and are depreciated using the straight-line method over the estimated useful lives of the assets (three to seven years), except leasehold improvements and software which are amortized over the lesser of the estimated useful lives of the asset or the remaining lease/license term.
	Goodwill and Intangible Assets
	We record goodwill and other intangible assets based on the fair value of the assets acquired. In determining the fair value of the assets acquired, we utilize extensive accounting estimates and judgments to allocate the purchase price to the fair value of the net tangible and intangible assets acquired. We use the discounted cash flow method to estimate the value of intangible assets acquired. The estimates used to value and amortize intangible assets are consistent with the plans and estimates that we use to manage our business and are based on available historical information and industry estimates and averages.
	We assess goodwill and intangible assets for impairment using fair value measurement techniques on an annual basis during the fourth quarter of the year, or more frequently if indicators of impairment exist. We perform an interim goodwill impairment test when it is more likely than not that the fair value of a reporting unit is less than the carrying amount. We operate as one reporting unit. The goodwill impairment test is a two step process. The first step compares the reporting unit's fair value to its net book value. If the fair value is less than the book value, the second step of the test compares the implied fair value of the reporting unit's goodwill with the carrying amount of that goodwill. If the carrying amount of goodwill exceeds its implied fair value, we would recognize an impairment loss equal to that excess amount. Determining the fair value of the implied goodwill is judgmental in nature and often involves the use of significant estimates and assumptions. These estimates and assumptions could have a significant impact on whether or not an impairment charge is recognized and also the magnitude of any such charge. Estimates of fair value are primarily determined using discounted cash flows and market comparisons. These approaches use significant estimates and assumptions, including the size and timing of deployments by our customers and related projections and timing of future cash flows, discount rates reflecting the risk inherent in future cash flows, perpetual growth rates, stage of products in development, determination of appropriate market comparables, and determination of whether a premium or discount should be applied to comparables.
	Investment in a Privately Held Company
	Through the second quarter of 2013, we had accounted for our investment in a privately held company under the equity method of accounting since we had exercised significant influence, but we did not have the elements of control that would require consolidation. The rights of the other investors were both protective and participating. Unless we were determined to be the primary beneficiary, these rights precluded us from consolidating the investment. The investment was recorded initially at cost as an investment in a privately held company, and subsequently was adjusted for equity in net income and cash contributions and distributions. As described in Note 2, during the nine months ended September 30, 2013, we recorded an impairment charge of $4.8 million relating to our investment. As of September 30, 2013, our investment in the privately held company was $0.
	Warranty Accrual
	We generally provide a warranty on our products for a period of one year; however, it may be longer for certain customers. Accordingly, we establish provisions for estimated product warranty costs at the time revenue is recognized based upon our historical activity and, additionally, for any known product warranty issues. Warranty provisions are recorded as a cost of net revenues. The determination of such provisions requires us to make estimates of product return rates and expected costs to replace or rework the products under warranty. When the actual product failure rates, cost of replacements and rework costs differ from our estimates, revisions to the estimated warranty accrual are made. Actual claims are charged against the warranty reserve.
	Guarantees and Indemnifications
	In the ordinary course of business, we have entered into agreements with customers that include indemnity provisions. To date, there have been no known events or circumstances that have resulted in any significant costs related to these indemnification provisions and, as a result, no liabilities have been recorded in the accompanying financial statements.
	Software Development Costs
	Software development costs are capitalized beginning when technological feasibility has been established and ending when a product is available for sale to customers. To date, the period between achieving technological feasibility and when the software is made available for sale to customers has been relatively short and software development costs qualifying for capitalization have not been significant. As such, all software development costs have been expensed as incurred in research and development expense.
	Stock-Based Compensation
	We have equity incentive plans under which incentive stock options have been granted to employees and restricted stock units and non-qualified stock options have been granted to employees and non-employees. We also have an employee stock purchase plan for all eligible employees.
	Our stock-based compensation cost is measured at the grant date, based on the estimated fair value of the award using either the Black-Scholes option pricing model for stock options or the grant date fair value of the stock on the date of the grant for restricted stock units, and is recognized as an expense over the employee's requisite service period. We have historically not granted performance based equity awards. However, in July 2013, we granted performance based equity awards which vest over a 15 month period, or earlier upon the achievement of certain milestones (see Note 3). The stock-based compensation expense attributable to awards under our 2007 Employee Stock Purchase Plan, or ESPP, was determined using the Black-Scholes option pricing model.
	We also grant awards to non-employees and determine the fair value of such stock-based compensation awards granted as either the fair value of the consideration received or the fair value of the equity instruments issued, whichever is more reliably measurable. If the fair value of the equity instruments issued is used, it is measured using the stock price and other measurement assumptions as of the earlier of (i) the date at which a commitment for performance by the counterparty to earn the equity instruments is reached, or (ii) the date at which the counterparty's performance is completed.
	We recognize excess tax benefits associated with stock-based compensation to stockholders' equity only when realized. When assessing whether excess tax benefits relating to stock-based compensation have been realized, we follow the “with and without” approach excluding any indirect effects to be realized until after the utilization of all other tax benefits available to us.
	Income Taxes
	We estimate income taxes based on the various jurisdictions where we conduct business. Significant judgment is required in determining our worldwide income tax provision. We estimate the current tax liability and assess temporary differences that result from differing treatments of certain items for tax and accounting purposes. These differences result in deferred tax assets and liabilities, which are reflected in our balance sheets. We then assess the likelihood that deferred tax assets will be realized. A valuation allowance is recorded when it is more likely than not that some of the deferred tax assets will not be realized. When a valuation allowance is established or increased, we record a corresponding tax expense in our statements of operations. When a valuation allowance is decreased, we record the corresponding tax benefit in our statements of operations. We review the need for a valuation allowance each interim period to reflect uncertainties about whether we will be able to utilize deferred tax assets before they expire. The valuation allowance analysis is based on estimates of taxable income for the jurisdictions in which we operate and the periods over which our deferred tax assets will be realizable.
	We recognize and measure benefits for uncertain tax positions using a two-step approach. The first step is to evaluate the tax position taken or expected to be taken in a tax return by determining if the weight of available evidence indicates that it is more likely than not that the tax position will be sustained upon audit, including resolution of any related appeals or litigation processes. For tax positions that are more likely than not of being sustained upon audit, the second step is to measure the tax benefit as the largest amount that has more than a 50% chance of being realized upon settlement. Significant judgment is required to evaluate uncertain tax positions. We evaluate uncertain tax positions on a quarterly basis. The evaluations are based upon a number of factors, including changes in facts or circumstances, changes in tax law, correspondence with tax authorities during the course of audits and effective settlement of audit issues.
	Segment Reporting
We are organized as, and operate in, one reportable segment: the design, development and sale of silicon integrated circuits. Products within this segment are embedded in electronic devices used to enable the delivery of multiple streams of high-definition, or HD, video and other multimedia content for entertainment purposes into and throughout the home. Our chief operating decision maker is our chief executive officer, or CEO. Our CEO reviews financial information presented on a consolidated basis for the purpose of evaluating financial performance and allocating resources. There are no segment managers who are held accountable for operations below the consolidated financial statement level. Our assets are primarily located in the United States and not allocated to any specific region. Therefore, geographic information is presented only for total revenue.
Recently Issued Accounting Standards
In February 2013, the Financial Accounting Standards Board (FASB) issued FASB Accounting Standards Update (ASU) No. 2013-02, Comprehensive Income (Topic 220) — Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. ASU 2013-02 requires an entity to provide information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, an entity is required to present, either on the face of the financial statements or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income, but only if the amount reclassified is required under GAAP to be reclassified to net income in its entirety in the same reporting period. For amounts that are not required to be reclassified in their entirety to net income, an entity is required to cross-reference to other disclosures that provide additional details about those amounts. ASU 2013-02 is effective prospectively for reporting periods beginning after December 15, 2012. The adoption of this ASU did not have a material impact on our financial statements.
In July 2013, the FASB issued ASU No. 2013-11, Income Taxes (Topic 740), Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carry forward, a Similar Tax Loss, or a Tax Credit Carry forward Exists (a consensus of the FASB Emerging Issues Task Force). The amendments in this ASU state that an unrecognized tax benefit, or a portion of an unrecognized tax benefit, should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carry forward, a similar tax loss, or a tax credit carry forward, subject to certain exceptions, in which case such an unrecognized tax benefit should be presented in the financial statements as a liability. The amendments in this ASU are effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. We do not expect the adoption of this update to ASC 740 to have a material impact on our financial position, results of operations or cash flows.
There have been no other recent accounting standards, or changes in accounting standards, during the nine months ended September 30, 2013, as compared to the recent accounting standards described in the Annual Report, that are of material significance, or have potential material significance, to us.

Supplemental_Financial_Informa

Supplemental Financial Information	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Supplemental Financial Information	'
	Supplemental Financial Information
	Marketable Securities
	We have marketable securities and financial instruments that are classified as either available-for-sale or trading securities. As of September 30, 2013, our short-term investment portfolio included $0.4 million of trading securities invested in a defined set of mutual funds directed by the participants in our non-qualified deferred compensation plan. As of September 30, 2013 these securities had net unrealized gains of $57,000 and a cost basis of $0.3 million. As of September 30, 2013, our short-term investment portfolio also included $0.5 million of trading securities invested in principal and interest guaranteed bank and time deposit accounts.
	The following tables summarize available-for-sale investments by security type as of September 30, 2013 and December 31, 2012 (in thousands):
		As of September 30, 2013
		Cost				Gross				Gross			Fair Market
						Unrealized				Unrealized			Value
						Gains				Losses
	Available-for-sale securities:
	Commercial paper	$	4,495			$	—			$	(1	)	$	4,494
	Corporate notes/bonds	54,100				95				—			54,195
	Total marketable securities, short-term	58,595				95				(1		)	58,689
	Corporate notes/bonds, long-term	71,961				21				(89		)	71,893
	U.S. treasury and agency notes/bonds, long-term	2,000				1				—			2,001
	Total	$	132,556			$	117			$	(90	)	$	132,583
		As of December 31, 2012
		Cost				Gross				Gross			Fair Market
						Unrealized				Unrealized			Value
						Gains				Losses
	Available-for-sale securities:
	Commercial paper	$	6,988			$	11			$	(1	)	$	6,998
	Corporate notes/bonds	67,944				56				(10		)	67,990
	U.S. treasury and agency notes/bonds	3,000				5				—			3,005
	State and municipal bonds	1,235				3				—			1,238
	Total marketable securities, short-term	79,167				75				(11		)	79,231
	Corporate notes/bonds, long-term	71,648				146				(46		)	71,748
	Total	$	150,815			$	221			$	(57	)	$	150,979
	Realized gains on our available-for-sale securities for the three months ended September 30, 2013 and 2012 and the nine months ended September 30, 2013 and 2012 were $41,000, $2,000, $50,000 and $13,000, respectively.
	The following table summarizes the contractual maturities of our available-for-sale securities (in thousands):
		As of September 30,
		2013
	Less than one year	$	58,689
	Due in one to five years	73,894
	Due after five years	—
		$	132,583
	Fair Value of Financial Instruments
	We determine a fair value measurement based on the assumptions a market participant would use in pricing an asset or liability. Accounting Standards Codification, or ASC, 820 establishes a three-level hierarchy making a distinction between market participant assumptions based on (i) unadjusted quoted prices for identical assets or liabilities in an active market (Level 1), (ii) quoted prices in markets that are not active or inputs that are observable either directly or indirectly for substantially the full term of the asset or liability (Level 2), and (iii) prices or valuation techniques that require inputs that are both unobservable and significant to the overall fair value measurement (Level 3).
	Cash and cash equivalents consist primarily of bank deposits with third-party financial institutions and highly liquid money market securities with original maturities at date of purchase of 90 days or less and are stated at cost which approximates fair value and are classified as Level 1 assets.
	Marketable securities are recorded at fair value, defined as the exit price in the principal market in which we would transact, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Level 1 instruments are valued based on quoted market prices in active markets for identical instruments and include our investments in money market and mutual funds. Level 2 securities are valued using quoted market prices for similar instruments, non-binding market prices that are corroborated by observable market data, or discounted cash flow techniques and include our investments in corporate bonds and notes, U.S. government agency securities, U.S. treasury bills, state and municipal bonds and commercial paper.
	Our non-qualified deferred compensation plan and employee pension plan liabilities are classified as Level 1 liabilities within the hierarchy. The fair values of the liabilities are directly related to the valuation of the short-term and long-term investments held in trust for the plan. Hence, the carrying value of the non-qualified deferred compensation liability and employee pension plan liability represents the fair value of the investment assets.
	Level 3 instruments are valued based on unobservable inputs that are supported by little or no market activity and reflect our own assumptions in measuring fair value. We have no assets classified as Level 3 instruments. There were no transfers between different levels during the three months ended September 30, 2013.
	The valuation of contingent consideration is based on a probability-weighted earnouts model which relies primarily on estimates of milestone achievements and discount rates applicable for the period expected payout. The most significant unobservable input used in the determination of estimated fair value of contingent consideration is the estimates on the likelihood of milestone achievements, which directly correlates to the fair value recognized in the unaudited condensed consolidated balance sheets.
	The fair value of this liability is estimated quarterly by management based on inputs received from our engineering and finance personnel. The determination of the milestone achievement is performed by our engineering department and reviewed by the accounting department. Potential valuation adjustments are made as the progress toward achieving milestones becomes determinable with the impact of such adjustments being recorded through other income, net.
	The fair value measurements of our cash equivalents, marketable securities, contingent consideration and non-qualified deferred compensation plan consisted of the following as of September 30, 2013 and December 31, 2012 (in thousands):
		Fair Value Measurements as of September 30, 2013
		Total				Level 1				Level 2			Level 3
	Assets:
	Cash equivalents	$	14,308			$	14,308			$	—		$	—
	Short-term investments:
	Commercial paper	4,494				—				4,494			—
	Corporate notes/bonds	54,195				—				54,195			—
	Mutual funds	407				407				—			—
	Bank and time deposits	453				453				—			—
	Long-term investments:
	Corporate notes/bonds	71,893				—				71,893			—
	U.S. treasury and agency notes/bonds	2,001				—				2,001			—
	Total assets at fair value	$	147,751			$	15,168			$	132,583		$	—
	Liabilities:
	Employee stock-based compensation guarantees	$	28			$	—			$	—		$	28
	Non-qualified deferred compensation plan	407				407				—			—
	Total liabilities at fair value	$	435			$	407			$	—		$	28
		Fair Value Measurements as of December 31, 2012
		Total				Level 1				Level 2			Level 3
Assets:
Cash equivalents	$	2,083			$	2,083			$	—		$	—
Short-term investments:
Commercial paper	6,998				—				6,998			—
Corporate notes/bonds	67,990				—				67,990			—
U.S. treasury and agency notes/bonds	3,005				—				3,005			—
State and municipal bonds	1,238				—				1,238			—
Mutual funds	368				368				—			—
Bank and time deposits	382				382				—			—
Long-term investments:
Corporate notes/bonds	71,748				—				71,748			—
Total assets at fair value	$	153,812			$	2,833			$	150,979		$	—
Liabilities:
Acquisition related contingent consideration	$	131			$	—			$	—		$	131
Employee stock-based compensation guarantees	152				—				—			152
Non-qualified deferred compensation plan	368				368				—			—
Total liabilities at fair value	$	651			$	368			$	—		$	283
The following table represents the change in level 3 liabilities which relate to acquisition related contingent consideration and employee stock compensation guarantees (in thousands):
	Fair Value Measurement Using Significant Unobservable Inputs (Level 3)
	Acquisition related contingent consideration				Employee stock-based compensation guarantees				Total
Liability as of December 31, 2012	$	131			$	152			$	283
Adjustments to fair value	(131		)		—				(131		)
Decrease in compensation expense	—				(124		)		(124		)
Liability as of September 30, 2013	$	—			$	28			$	28
On July 6, 2012, in connection with our acquisition of specific direct broadcast satellite intellectual property and corresponding technologies from PLX Technology, Inc., or PLX, a liability was recognized for an estimate of the acquisition date fair value of the contingent milestone consideration based on the probability of achieving the milestones and the probability-weighted discount on cash flows. Changes in the fair value of the contingent milestone consideration subsequent to the acquisition date are recognized in the statements of operations. See Note 3 for further discussion of the fair value measurement of the acquisition related contingent consideration.
The employee stock-based compensation guarantees represent compensation liability associated with certain restricted stock unit grants. Based on the terms of these grants, a cash payment is required to be made in the event that the stock price at the date of vesting falls below the grant date price. The fair value of this liability is remeasured quarterly using the Black-Scholes option pricing model which considers the potential payout, the remaining time until payout, volatility of the underlying shares, and the risk-free interest rate to calculate the liability that may be due under the arrangement.
Nonrecurring Fair Value Measurements
We measure certain assets at fair value on a nonrecurring basis. These assets include cost and equity method investments when they are deemed to be other-than-temporarily impaired, assets acquired and liabilities assumed in an acquisition or in a non-monetary exchange, and property, plant and equipment and intangible assets that are written down to fair value when they are held for sale or determined to be impaired. During the nine months ended September 30, 2013, we determined that we had incurred an other-than-temporary impairment of our investment in a privately held company and we wrote off the remainder of the investment of approximately $4.8 million. During the nine months ended September 30, 2012, we did not have any significant assets or liabilities that were measured at fair value on a nonrecurring basis in periods subsequent to initial recognition.
Inventory
The components of inventory were as follows (in thousands):
	September 30, 2013				December 31, 2012
Work in process	$	8,061			$	16,353
Finished goods	7,055				10,042
Total inventory	$	15,116			$	26,395
Property and Equipment
Property and equipment consisted of the following (in thousands, except for years):
	Useful Lives		September 30, 2013				December 31, 2012
	(in years)
Office and laboratory equipment	5		$	23,430			$	20,629
Computer equipment	5-Mar		7,617				6,473
Furniture and fixtures	7-Mar		2,193				2,032
Leasehold improvements	Lease term		7,090				6,438
Software	3-Jan		4,663				2,913
Construction in progress			253				846
			45,246				39,331
Accumulated depreciation			(27,318		)		(21,702		)
Property and equipment, net			$	17,928			$	17,629
Depreciation and amortization expense for the three months ended September 30, 2013 and 2012 and the nine months ended September 30, 2013 and 2012 was $2.2 million, $1.4 million, $6.3 million and $3.9 million, respectively.
Goodwill and Intangible Assets
On June 5, 2013, we acquired the intellectual property assets of Mobius Semiconductor, Inc., or Mobius, and recognized $0.8 million of goodwill in connection with the acquisition.
On July 6, 2012, we acquired specific direct broadcast satellite intellectual property and corresponding technologies from PLX and recognized $0.7 million of goodwill in connection with the acquisition.
On April 12, 2012, we completed our acquisition of assets from Trident Microsystems, Inc. and certain of its subsidiaries, collectively Trident, used in or related to Trident's set-top box business, or STB business, and recognized $4.0 million of goodwill in connection with the acquisition. During the nine months ended September 30, 2013, we finalized the acquisition related hold back payments with Trident. The finalization of these amounts resulted in a decrease to goodwill of $0.7 million. As of September 30, 2013, the goodwill related to the acquisition of Trident was $3.3 million.
Intangible assets consisted of the following (in thousands):
		As of September 30, 2013
		Gross				Accumulated Amortization				Net
Developed technology		$	43,475			$	(12,709	)		$	30,766
In-process research and development		13,761				—				13,761
Total intangibles amortized to cost of net revenues		57,236				(12,709		)		44,527
Customer relationships		6,800				(1,336		)		5,464
Non-compete agreement		1,603				(1,107		)		496
Customer backlog		2,000				(2,000		)		—
Total intangibles amortized to operating expense		10,403				(4,443		)		5,960
Total intangible assets		$	67,639			$	(17,152	)		$	50,487
Investment in a Privately Held Company
In September 2011, we purchased shares of convertible preferred stock in Zenverge, Inc., a privately-held, venture capital funded technology company, for a total investment cost of $10.0 million, which at the time of the investment represented a 16.3% equity interest in the company. We also entered into a strategic partnership to co-develop an integrated chip that combines our MoCA functionality with this entity's independently developed technology. As a result of our joint development arrangement with this company and the appointment of our CEO as a member of the company's board of directors, we determined that the ability to exercise significant influence over the company existed and, accordingly, we accounted for this investment following the equity method. The investment was recorded initially at cost as an investment in a privately held company and was subsequently adjusted for our equity position in net operating results and cash contributions and distributions. In addition, we recorded a charge relating to our proportionate ownership percentage of the premium paid for our investment in excess of our share of their net worth. The fair value of this premium consisted of certain intangible asset and goodwill values as determined by a valuation calculation. These intangible assets represent the excess of the book value of the privately held company as compared to the valuation of the privately held company.
During the second quarter of 2013, we gave Zenverge notice of our intent to terminate the joint development arrangement and in July 2013, our CEO resigned from the board of directors of Zenverge. As a result, we determined that the ability to exercise significant influence over Zenverge no longer existed and we no longer accounted for the investment under the equity method. As such, we no longer recognize any earnings from our investment in Zenverge.
Additionally, during the second quarter of 2013, our preferred stock investment was converted into common stock based on the terms of a financing in which Zenverge raised additional funds where we did not participate. We then reviewed the available information to determine if our investment in Zenverge's common stock had indicators of possible impairment. As a result of the liquidation preferences held by the remaining preferred stockholders, we concluded that our common stock investment did not have any value and as a result, we had incurred an other-than-temporary impairment of our investment in Zenverge; we wrote off the remainder of the investment from $4.8 million to $0 in June 2013.
For the three and nine months ended September 30, 2013, the change in the carrying value of our investment was $0 and $5.9 million, respectively, which is reflected as a decrease in our investment. As of September 30, 2013 and December 31, 2012, the carrying amount of our investment in a privately held company was $0 and $5.9 million, respectively, which is the extent of our exposure related to our investment in this entity.
Accrued Warranty
The following table presents a roll forward of our product warranty liability, which is included within accrued expenses and other current liabilities in the unaudited condensed consolidated balance sheets (in thousands):
	Nine Months Ended September 30,
	2013
Beginning balance	$	448
Accruals for warranties issued during the period	134
Settlements made during the period	(21		)
Change in estimated warranty rate	(445		)
Expirations	(32		)
Ending balance	$	84
Accrued Bonuses
We maintain a discretionary management bonus plan. The potential bonus payments made under our plans are based significantly on the achievement of operational, financial and business development objectives for each calendar year. As of September 30, 2013 we believed that the achievement of our performance targets specified by the 2013 bonus plan was not probable. Therefore, as of September 30, 2013 we had no accrual for management bonuses.
Restructuring Activity
In order to rebalance our operations in an attempt to leverage synergies from our acquisitions and to refine our business operations, we have implemented two operational restructuring plans. As a result of these activities, we recorded a restructuring charge of $1.7 million in the nine months ended September 30, 2013. This plan resulted in a reduction of our personnel by 66 employees or approximately 10% of our workforce. In November 2012, we incurred a restructuring charge of $0.9 million, which resulted in a reduction of our personnel by 40 employees or approximately 6% of our workforce.
The following table presents a roll forward of our restructuring liability as of September 30, 2013, which is included within accrued payroll and benefits in the unaudited condensed consolidated balance sheets (in thousands):
		Restructuring Liability - Employee Separation Expenses
Liability as of January 1, 2012		$	—
Restructuring charges		897
Cash payments		(363		)
Liability as of December 31, 2012		534
Restructuring charges		1,694
Cash payments		(1,985		)
Liability as of September 30, 2013		$	243
Deferred Compensation
We have a non-qualified deferred compensation plan that permits certain key employees to defer portions of their compensation, subject to annual deferral limits, and have it credited to one or more investment options in the plan. At September 30, 2013, we had marketable securities totaling $0.4 million related to investments in equity securities that are held in a rabbi trust established under our non-qualified deferred compensation plan. The total related deferred compensation liability was $0.4 million at September 30, 2013, all of which was classified as a non-current liability and recorded in our unaudited condensed consolidated balance sheets under other long-term liabilities.
Purchase Commitments
We had firm purchase order commitments for the acquisition of inventory as of September 30, 2013 and December 31, 2012 of $8.3 million and $12.0 million, respectively.
Stock-Based Compensation
We have in effect equity incentive plans under which incentive stock options, non-qualified stock options and restricted stock units have been granted to employees, directors and consultants to purchase shares of our common stock at a price not less than the fair market value of the stock at the date of grant, except for certain options assumed in connection with a business combination. These equity plans include the 2007 Non-Employee Directors’ Stock Option Plan, under which we continue to grant non-qualified stock options, and the 2007 Equity Incentive Plan under which we continue to grant non-qualified stock options and restricted stock units. These plans are further described in our Annual Report on Form 10-K.
On April 8, 2012, our 2012 Inducement Award Plan became effective. This plan provides for the grant of non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards and other stock awards to eligible new employees or directors not previously employed by us. During the year ended December 31, 2012, we commenced granting non-qualified stock options and restricted stock units under this plan.
We also grant stock awards under our ESPP. Under the terms of the ESPP, eligible employees may purchase shares of our common stock at 85% of the fair market value of our common stock on the offering date or the purchase date, whichever is less. Purchase dates occur twice each year, with a “look-back” period of up to 12 months to determine the lowest common stock valuation date, either the offering date or the purchase date.
Stock-based compensation expense recognized in our unaudited condensed consolidated statements of operations for the three and nine months ended September 30, 2013 and 2012 includes compensation expense for stock-based options and awards granted subsequent to December 31, 2005, based on the grant date fair value. For options and awards granted, expenses are amortized under the straight-line method. Stock-based compensation expense recognized in the unaudited condensed consolidated statements of operations has been reduced for estimated forfeitures of options that are subject to vesting. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates.
We allocated stock-based compensation expense as follows (in thousands):
	Three Months Ended September 30,								Nine Months Ended September 30,
	2013				2012				2013			2012
Cost of net revenues	$	227			$	217			$	658		$	567
Research and development	2,766				2,030				6,730			5,554
Sales and marketing	510				675				1,324			1,679
General and administrative	1,089				1,283				3,109			3,182
Total stock-based compensation expense	$	4,592			$	4,205			$	11,821		$	10,982
Equity Incentive Plans
As part of our continual evaluation of the calculation of our stock-based compensation expense, we reviewed and updated our forfeiture rate, expected term and volatility assumptions during the three and nine months ended September 30, 2013 and there was no significant impact. The risk-free interest rate is based on zero coupon U.S. Treasury instruments with maturities similar to those of the expected term of the award being valued. Through June 30, 2013, we used a combination of our historical experience, the contractual term and the average option term of a comparable peer group to determine the expected life of our option grants. The peer group historical term was used due to the limited trading history of our common stock. The estimated volatility incorporated historical volatility of similar entities whose share prices are publicly available. Effective July 1, 2013, we no longer incorporate peer group data in determining our expected life and volatility assumptions. The expected dividend yield was based on our expectation of not paying dividends on common stock for the foreseeable future.
We granted options and other stock awards to consultants in connection with their service agreements. For the three months ended September 30, 2013 and 2012 and the nine months ended September 30, 2013 and 2012 we recorded stock-based compensation expense related to these awards of $0, $8,000, $9,000 and $46,000, respectively. The fair value of the awards was estimated using a Black-Scholes option-pricing model.
The fair value of stock options granted to employees, directors and consultants was estimated at the grant date using the following assumptions:
	Three Months Ended September 30,						Nine Months Ended September 30,
	2013			2012			2013		2012
Expected life (years)	5.4			5.2			5.3 - 5.4		5.1 - 5.2
Contractual term (years)	10			10			10		10
Risk-free interest rate	1.52	%		0.76	%		0.79% - 1.52%		0.76% - 1.09%
Expected volatility	89	%		90	%		89% - 90%		89% - 90%
Expected dividend yield	—			—			—		—
As of September 30, 2013, we estimated there were $33.2 million in total unrecognized compensation costs related to employee equity incentive agreements, which are expected to be recognized over a weighted-average period of 1.3 years.
For the three and nine months ended September 30, 2013 and 2012 the fair value of expected shares to be issued under the ESPP were estimated using the following assumptions:
	Three Months Ended September 30,				Nine Months Ended September 30,
	2013		2012		2013		2012
Expected life (years)	0.5 to 1.0		0.5 to 1.0		0.5 to 1.0		0.5 to 1.0
Risk-free interest rate	0.08% to 0.18%		0.13% to 0.19%		0.08% to 0.19%		0.05% to 0.22%
Expected volatility	47% to 63%		64% to 84%		47% to 84%		58% to 100%
Expected dividend yield	—		—		—		—
For the three months ended September 30, 2013 and 2012 and the nine months ended September 30, 2013 and 2012 we recorded stock-based compensation expense related to awards under the ESPP totaling $0.5 million, $0.6 million, $1.2 million and $1.8 million, respectively. As of September 30, 2013 we estimated there were $0.5 million of unrecognized compensation costs related to the shares expected to be purchased through the ESPP, which are expected to be recognized over a remaining weighted-average period of 0.4 years.
Stock Options
During the three and nine months ended September 30, 2013, we granted stock options to purchase 0.2 million and 1.2 million shares of our common stock, respectively. During the three and nine months ended September 30, 2013, stock options to purchase approximately 0.1 million and 0.6 million shares of common stock were exercised, respectively. During the three and nine months ended September 30, 2013, options to purchase 0.3 million and 1.0 million shares of common stock were forfeited or expired, respectively. As of September 30, 2013, we had outstanding options to purchase approximately 10.2 million shares of common stock.
Restricted Stock Units
During the three and nine months ended September 30, 2013, 0.1 million and 1.1 million shares of our common stock vested and were released pursuant to outstanding restricted stock units, respectively. As of September 30, 2013, we had approximately 6.8 million shares of common stock subject to restricted stock units outstanding.
During the three and nine months ended September 30, 2013, 3.5 million and 5.4 million restricted stock units were granted, respectively, and 0.3 million and 0.7 million restricted stock units were forfeited, respectively. Generally, restricted stock units vest annually with a term of one year to four years from the date of the grant on the anniversary date of the grant or on a predetermined quarterly vesting date following the anniversary date of the grant. The related compensation expense of restricted stock units is being recognized ratably over the service period.

Business_Combinations

Business Combinations	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Business Combinations	'
	Business Combinations
	Mobius Semiconductor
	On June 5, 2013, we acquired the assets of Mobius Semiconductor, Inc., or Mobius, a leading product development company focused on low power, high performance analog mixed-signal semiconductor solutions for a total cash consideration of $13.0 million. The acquired technology will enable Entropic to provide cable and satellite operators with solutions that encompass system designs that are low power, broadband, high-speed, and which capture the full bandwidth of the signal payload - to drive more entertainment streams and IP services to more connected devices in the home. This technology can also be leveraged by global satellite service providers to migrate to digital single-wire communications.
	In connection with the completion of the Mobius transaction, certain Mobius personnel entered into employment arrangements with Entropic. On July 18, 2013 we granted restricted stock units, or RSUs, for an aggregate 3.2 million shares of common stock as long-term retention grants to certain employees of Mobius who joined Entropic. The RSUs had an estimated value of $14.0 million on the grant date. Approximately 0.9 million RSUs vest over a 15 month period, or earlier upon the achievement of certain milestones and the remaining 2.3 million RSUs vest over a 36 month period. These RSUs are being accounted for as compensation expense over the vesting periods. We currently estimate that the performance based milestones related to the 0.9 million RSUs will not be achieved prior to the 15 month service period.
	On the acquisition date, based on preliminary estimates of fair value, we allocated the total consideration to the following assets (in thousands):
		Allocation of
		Purchase Price
	Intangible assets	$	12,239
	Goodwill	752
	Prepaid expenses	25
	Property and equipment, net	9
	Total purchase price	$	13,025
	The allocation of the purchase price to the net assets acquired and liabilities assumed resulted in the recognition of the following intangible assets (in thousands, except for years):
						Estimated Useful
		Amount				Life (in years)
	In-process research and development	$	12,136			*
	Non-compete agreement	103				2
	Total intangible assets	$	12,239
	*Upon completion of each project, the related in-process research and development, or IPR&D, asset will be amortized over its estimated useful life. If any of the projects are abandoned or the forecast of the project indicates that the fair value is less than the carrying amount, we will be required to write down the related IPR&D asset.
	Under the purchase method of accounting, the identifiable net assets acquired and liabilities assumed were recognized and measured as of the acquisition date based on their estimated fair values. In the determination of the fair value of the in-process research and development, or IPR&D, various factors were considered, such as future revenue contributions, additional licensing costs associated with the underlying technology, and contributory asset charges. The fair value of the IPR&D was calculated using an income approach and the rate utilized to discount net future cash flows to their present values was based on a weighted average cost of capital of approximately 21%. This discount rate was determined after considering our cost of debt adjusted for a risk premium that market participants would require in an investment in companies that are at similar stages of development as Mobius.
	IPR&D will not be amortized until the product is complete, at which time it will be amortized over the estimated useful life of the developed technology. The useful life of the IPR&D will be estimated as the period over which the asset is expected to contribute directly or indirectly to our future cash flows. Up to the point that the product is complete, we will assess the IPR&D annually for impairment, or more frequently if certain indicators are present.
	The excess of the fair value of the total consideration over the estimated fair value of the net assets was recorded as goodwill. We allocated $0.8 million of the total consideration to goodwill. We consider the acquired business an addition to our product development effort and not an additional reporting unit or operating segment. The goodwill recognized is expected to be deductible for income tax purposes.
	PLX Technology
	On July 6, 2012, we acquired specific direct broadcast satellite intellectual property and corresponding technologies from PLX, a leading global supplier of high-speed connectivity solutions enabling emerging data center architectures. The purchased assets relate to the design and development of a digital channel stacking switch semiconductor product. The purchase price included a one-time licensing fee for intellectual property which is related to the acquired assets. The total consideration for the net assets and the licensing fee is up to $11.9 million, consisting of an initial cash payment of $6.9 million, which was paid to PLX in July 2012, and additional consideration of up to $5.0 million payable upon the achievement of a technical product development milestone and a license approval milestone. All acquisition costs related to the transaction were expensed as incurred. The total acquisition date fair value of the consideration was estimated at $10.0 million as follows (in thousands):
	Initial cash payment to PLX		$	6,874
	Estimated fair value of contingent milestone consideration		3,100
	Total purchase price		$	9,974
	On the acquisition date, a liability was recognized for an estimate of the acquisition date fair value of the contingent milestone consideration based on the probability of achieving the milestones and the probability-weighted discount on cash flows. Any change in the fair value of the contingent milestone consideration subsequent to the acquisition date is recognized in the statements of operations. During the year ended December 31, 2012, we reassessed the fair value of the remaining contingent consideration at $3.5 million and recorded the increase of $0.4 million in the fair value of the remaining contingent consideration. In November 2012 we agreed to settle the first milestone and $3.4 million of additional consideration was paid.
	This fair value measurement of the contingent consideration is based on significant inputs not observed in the market and thus represents a Level 3 measurement. Level 3 instruments are valued based on unobservable inputs that are supported by little or no market activity and reflect our own assumptions in measuring fair value. In June 2013, we reassessed the likelihood of achieving the second milestone and determined that the milestone would not be achieved. As such, we reversed the remaining $0.1 million accrual related to the fair value of the contingent milestone during the second quarter of 2013.
	On the acquisition date, we allocated the total consideration to the following assets (in thousands):
			Allocation of
			Purchase Price
	Property and equipment, net		$	241
	Intangible assets		9,200
	Goodwill		652
	Employee compensation liabilities		(119		)
	Total purchase price		$	9,974
	The allocation of the purchase price to the net assets acquired and liabilities assumed resulted in the recognition of the following intangible assets (in thousands, except for years):
							Estimated Useful
			Amount				Life (in years)
	In-process research and development		$	6,200			*
	Customer relationships		2,900				7
	Non-compete agreement		100				2
	Total intangible assets		$	9,200
	*Upon completion of each project, the related IPR&D asset will be amortized over its estimated useful life. If any of the projects are abandoned or the forecast of the project indicates that the fair value is less than the carrying amount, we will be required to write down the related IPR&D asset.
	Under the purchase method of accounting, the identifiable net assets acquired and liabilities assumed were recognized and measured as of the acquisition date based on their estimated fair values. In the determination of the fair value of the IPR&D, various factors were considered, such as future revenue contributions, additional licensing costs associated with the underlying technology, and contributory asset charges. The fair value of the IPR&D was calculated using an income approach and the rate utilized to discount net future cash flows to their present values was based on a weighted average cost of capital of approximately 41%. This discount rate was determined after considering our cost of debt adjusted for a risk premium that market participants would require in an investment in companies that are at similar stages of development as PLX.
	IPR&D will not be amortized until the product is complete, at which time it will be amortized over the estimated useful life of the developed technology. The useful life of the IPR&D will be estimated as the period over which the asset is expected to contribute directly or indirectly to our future cash flows. Up to the point that the product is complete, we will assess the IPR&D annually for impairment, or more frequently if certain indicators are present.
	The excess of the fair value of the total consideration over the estimated fair value of the net assets was recorded as goodwill. We allocated $0.7 million of the total consideration to goodwill. We consider the acquired business an addition to our product development effort and not an additional reporting unit or operating segment. The goodwill recognized is expected to be deductible for income tax purposes.
	STB Business
	On April 12, 2012, we completed our acquisition of assets related to the Set-top Box, or STB, business of Trident Microsystems, Inc. and certain of its subsidiaries, collectively Trident, for a purchase price of $74.1 million. The purchase price included working capital assets of $24.4 million and assumed employee liabilities of $2.3 million, pursuant to the terms of our Asset Purchase Agreement with Trident, dated January 18, 2012, as amended, or Purchase Agreement.
	Pursuant to the Purchase Agreement, we acquired all of Trident's specific STB business system-on-a-chip solutions, certain patents and all other intellectual property owned by Trident, certain contracts and prepaid expenses, and certain tangible assets, accounts receivable, inventory and equipment. Trident retained its digital television, PC television, audio and terrestrial demodulator businesses and we licensed to Trident certain of the acquired patents and intellectual property for use in the retained businesses. We also acquired leased facilities in Austin, Texas, San Diego, California, Belfast, Northern Ireland and Hyderabad, India and the right to use other facilities of Trident under short term Facilities Use Agreements.
	Our acquisition of the STB business from Trident has been accounted for under the acquisition method of accounting in accordance with ASC Topic 805, "Business Combinations." Under the acquisition method of accounting, the total purchase price was allocated to the net tangible and intangible assets of the STB business in connection with our acquisition of the STB business from Trident, based on their estimated fair values. During the first quarter of 2013 we finalized certain post-closing purchase price adjustments with Trident, resulting in a $0.7 million reduction in the purchase price. This adjustment to the purchase price has been reflected as a reduction of goodwill.
	The allocation of the purchase price to the assets acquired and liabilities assumed was as follows (in thousands):
			Allocation of
			Purchase Price
	Accounts receivable		$	8,066
	Prepaid inventory		4,310
	Inventories		7,091
	Prepaid expenses and other assets		4,966
	Property and equipment, net		2,433
	Other long term assets		125
	Intangible assets		46,200
	Goodwill		3,285
Employee compensation liabilities		(2,342		)
Total purchase price		$	74,134
The allocation of the purchase price to the net assets acquired and liabilities assumed resulted in the recognition of the following intangible assets (in thousands, except for years):
						Estimated Useful
		Amount				Life (in years)
Developed technology		$	32,400			4
In-process research and development		6,500				*
Customer relationships		3,900				7
Non-compete agreement		1,400				2
Customer backlog		2,000				1
Total intangible assets		$	46,200
*Upon completion of each project, the related IPR&D asset will be amortized over its estimated useful life. If any of the projects are abandoned or the forecast of the project indicates that the fair value is less than the carrying amount, we will be required to write down the related IPR&D asset.
The fair value of the identified intangible assets acquired in connection with our acquisitions was estimated using an income approach. Under the income approach, an intangible asset's fair value is equal to the present value of future economic benefits to be derived from ownership of the asset. Indications of value are developed by discounting future net cash flows to their present value at market-based rates of return. The goodwill recognized as a result of our acquisitions was primarily attributable to the value of the workforce that became our employees following the closing of the acquisitions. We consider the acquired business an addition to our product development efforts and product offerings and not an additional reporting unit or operating segment. The goodwill recognized is expected to be deductible for income tax purposes. The useful life of the intangible assets for amortization purposes was determined by considering the period of expected cash flows used to measure the fair value of the intangible assets adjusted as appropriate for the entity-specific factors including legal, regulatory, contractual, competitive economic or other factors that may limit the useful life of intangible assets.
Supplemental Pro Forma Information
The following unaudited pro forma information presents the consolidated results of operations of Entropic and Trident as if the acquisition had occurred at the beginning of the period presented, with pro forma adjustments to give effect to amortization of intangible assets and certain other adjustments (in thousands, except per share amounts):
	Three Months Ended September 30,				Nine Months Ended September 30,
	2012				2012
Net revenues	$	89,825			$	254,697
Net income (loss)	527				(2,870		)
Net income (loss) per share - basic and diluted	0.01				(0.03		)
Adjustments to the supplemental pro forma combined results of operations were as follows (in thousands):
	Three Months Ended September 30,				Nine Months Ended September 30,
	2012				2012
Net impact of the change in amortization of intangibles	$	—			$	(733	)
Transaction related expenses related to acquisition	183				4,484
Reorganization expenses related to Trident's bankruptcy filing	—				1,471
Adjust taxes to the blended rate after business combination	(64		)		3,954
	$	119			$	9,176
These unaudited pro forma condensed consolidated financial results have been prepared for illustrative purposes only and do not purport to be indicative of the results of operations that actually would have resulted had the acquisition occurred on the first day of the earliest period presented, or of the future results of the consolidated entities. The unaudited pro forma condensed consolidated financial information does not reflect any operating efficiencies and cost savings that may be realized from the integration of the acquisition.

Derivative_Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Instruments	'
		Derivative Instruments
	In the fourth quarter of 2012 we implemented a policy to manage some of our foreign currency exchange rate risk through the purchase of foreign currency exchange contracts that hedge against the short-term effect of currency fluctuations. Our policy is to enter into foreign currency forward contracts with maturities generally less than 12 months that mitigate the effect of rate fluctuations on certain local currency denominated operating expenses. All derivative instruments are recorded at fair value in either prepaid expenses and other current assets or accrued liabilities. Gains or losses arising from the remeasurement of these contracts to fair value each period are recorded in other income, net. We use quoted prices to value our derivative instruments. During the three and nine months ended September 30, 2013, we recorded a gain of $0.1 million and $31,000, respectively, related to these fair value hedging contracts. As of September 30, 2013, we had outstanding contracts to purchase $14.0 million of Chinese yuan, $2.8 million of Indian rupees and $1.2 million of British pounds which settle during the course of the next 12 months.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Income Taxes	'
	Income Taxes
	In order to determine our quarterly provision for income taxes, we use an estimated annual effective tax rate, which is based on expected annual income and statutory tax rates in the various jurisdictions in which we operate. Certain significant or unusual items are separately recognized in the quarter during which they occur and can be a source of variability in the effective tax rates from quarter to quarter.
	During the second quarter of 2013, we evaluated our net deferred income tax assets, including an assessment of the cumulative income or loss over the prior three-year period and future periods, to determine if a valuation allowance is required. A significant negative factor in our assessment was the expectation that we may be in a three-year historical cumulative loss as of the end of the first quarter of fiscal 2014 and through the near term, as profitable quarters in the earlier years are removed from the rolling three-year calculation. After considering our recent history of losses and management's expectation of additional near-term losses, during the second quarter of 2013, we recorded a valuation allowance of approximately $26.7 million on our net deferred tax assets with a corresponding charge to our income tax provision. We continue to assess the need for a valuation allowance on deferred tax assets by evaluating both positive and negative evidence that may exist.
	Income tax benefit for the three months ended September 30, 2013 was $0.9 million compared to an expense of $1.2 million for the three months ended September 30, 2012, or 7% and 74% of pre-tax (loss) income, respectively. The effective tax rate for the three months ended September 30, 2013 differs from the federal statutory rate primarily due to the establishment of the valuation allowance against our net deferred tax assets in the second quarter of 2013. The effective tax rate for the three months ended September 30, 2012 was comprised of federal expense at statutory rates plus a net increase in our tax rate of 39% due to the impact of certain permanent items and reserves for uncertain tax positions. Our net state income tax rate was nominal for the three months ended September 30, 2013 and September 30, 2012 due to the impact of the California single sales factor election to calculate our tax liability.
	Income tax expense for the nine months ended September 30, 2013 was $21.7 million compared to $4.2 million for the nine months ended September 30, 2012, or (67)% and 49% of pre-tax (loss) income, respectively. The effective tax rate for the nine months ended September 30, 2013 differs from the federal statutory rate primarily due to the establishment of the valuation allowance against our net deferred tax assets in the second quarter of 2013. The effective tax rate for the nine months ended September 30, 2012 was comprised of federal expense at statutory rates plus an increase in our tax rate of 14% due to the impact of certain permanent items and reserves for uncertain tax positions. Our net state income tax rate was nominal for the nine months ended September 30, 2013 and September 30, 2012 due to the impact of the California single sales factor election to calculate our tax liability.
	We file U.S., state and international income tax returns in jurisdictions with various statutes of limitations. Our consolidated federal tax return and any significant state tax returns are not currently under examination.

Net_Loss_Income_Per_Common_Sha

Net (Loss) Income Per Common Share	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Net (Loss) Income Per Common Share	'
	Net (Loss) Income Per Common Share
	We compute basic net (loss) income per share of common stock by dividing net (loss) income by the weighted average number of shares of common stock outstanding for the period. Diluted net (loss) income per share is computed using the weighted average number of shares of common stock and dilutive common equivalent shares outstanding for the period. Common equivalent shares from stock options and other common stock equivalents are excluded from the computation when their effect is antidilutive.
	The following table sets forth the computation of basic and diluted net (loss) income per share for the periods indicated (in thousands, except per share data):
		Three Months Ended September 30,					Nine Months Ended September 30,
		2013			2012		2013			2012
	Numerator:
	Net (loss) income—basic and diluted	$	(11,935	)	$	408	$	(54,252	)	$	4,474
	Denominator:
	Weighted average number of shares of common stock outstanding—basic	91,069			88,399		90,225			87,913
	Effect of dilutive securities:
	ESPP shares	—			97		—			75
	Stock award common share equivalents	—			2,389		—			1,930
	Weighted average number of shares of common stock outstanding—diluted	91,069			90,885		90,225			89,918
	Net (loss) income per share—basic	$	(0.13	)	$	—	$	(0.60	)	$	0.05
	Net (loss) income per share—diluted	$	(0.13	)	$	—	$	(0.60	)	$	0.05
	For the three months ended September 30, 2013 and 2012 and the nine months ended September 30, 2013 and 2012, potentially dilutive securities covering 17.1 million, 5.8 million, 14.8 million and 6.3 million shares of our common stock, respectively, were not included in the diluted net (loss) income per share calculations because they would be antidilutive.

Share_Repurchase_Program

Share Repurchase Program	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Share Repurchase Program [Text Block]	'
	7.     Share Repurchase Program
	In September 2013, our Board of Directors approved a share repurchase program authorizing us to repurchase up to $30.0 million of our common stock. Purchases under this program may be made from time to time through 10b5-1 programs, open market purchases, or privately negotiated transactions. The number of shares ultimately repurchased, and the timing of the purchases, depend on market conditions, share price, and other factors. Purchases under this program may be made until September 30, 2014, however, the program may be discontinued at any time.
	During the three months ended September 30, 2013, no purchases were made under this program.

Significant_Customer_and_Geogr

Significant Customer and Geographic Information	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Significant Customer, Vendor and Geographic Information	'
	Significant Customer and Geographic Information
	Customers
	Based on direct shipments, customers that exceeded 10% of total net revenues or accounts receivable were as follows:
		Net Revenues					Net Revenues					Accounts Receivable
		Three Months Ended September 30,					Nine Months Ended September 30,					As of September 30,		As of December 31,
		2013		2012			2013			2012		2013		2012
	Foxconn Electronics, Inc.	23	%	*			17	%		*		22	%	*
	Motorola Mobility, Inc.	*		12	%		*			13	%	*		11	%
	Wistron NeWeb Corporation	21	%	20	%		17	%		22	%	23	%	29	%
	*	Customer accounted for less than 10% of total net revenues or accounts receivable, as applicable, for the period indicated.
	Geographic Information
	Net revenues are allocated to the geographic region based on the shipping destination of customer orders. Net revenues by geographic region were as follows (in thousands):
		Three Months Ended September 30,							Nine Months Ended September 30,
		2013			2012				2013			2012
	Asia	$	44,620		$	81,102			$	171,384		$	204,109
	Europe	686			1,787				2,927			5,036
	United States	2,246			1,378				5,644			2,388
	North America, other	8,824			5,558				21,490			20,447
	Total	$	56,376		$	89,825			$	201,445		$	231,980
	As of September 30, 2013 and December 31, 2012, long-lived assets, which represent property, plant and equipment, net of accumulated depreciation, and lease deposits, located outside of the United States were $7.5 million and $6.3 million, respectively.

Legal_Matters

Legal Matters	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Legal Matters	'
	Legal Matters
	From time to time, we may be subject to various legal proceedings and claims arising in the ordinary course of business. We assess contingencies to determine the degree of probability and range of possible loss for potential accrual in our financial statements. An estimated loss contingency is accrued in the financial statements if it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. There are no material outstanding claims or litigation against us at September 30, 2013.

Organization_and_Summary_of_Si1

Organization and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Business	'
	Business
	Entropic Communications, Inc. was organized under the laws of the state of Delaware on January 31, 2001. Entropic Communications is a leading fabless semiconductor company that designs, develops and markets semiconductor solutions to enable home entertainment. Our technologies change the way traditional broadcast video, streaming video, and other multimedia content such as movies, music, games and photos are brought into, distributed and processed throughout the home.
Basis of Presentation	'
	Basis of Presentation
	The accompanying interim unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles, or GAAP.
	The accompanying unaudited condensed consolidated financial statements include our accounts and those of our wholly-owned subsidiaries. All inter-company accounts and transactions have been eliminated in consolidation.
	The accompanying unaudited condensed consolidated financial statements include all adjustments, consisting of normal recurring accruals, which we consider necessary for a fair presentation of the financial position and results of operations for the periods presented.
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the unaudited condensed consolidated financial statements and these accompanying notes. Among the significant estimates affecting the unaudited condensed consolidated financial statements are those related to business combinations, allowance for doubtful accounts, inventory reserves, long-lived assets (including intangible assets), warranty reserves, accrued bonuses, income taxes, valuation of equity securities and stock-based compensation. On an ongoing basis, management reviews its estimates based upon currently available information. Actual results could differ materially from those estimates.
Foreign Currency Translation	'
	Foreign Currency Translation
	The functional currency for our foreign subsidiaries is the local currency. Assets and liabilities denominated in foreign currencies are translated using the exchange rates on the balance sheet dates. Net revenues and expenses are translated using the average exchange rates prevailing during the year. Any translation adjustments resulting from this process are shown as a component of accumulated other comprehensive income within stockholders' equity in the unaudited condensed consolidated balance sheets. Foreign currency transaction gains and losses are reported in operating expenses in the unaudited condensed consolidated statements of operations.
Derivative Financial Instruments	'
	Derivative Financial Instruments
	Our primary objective for holding derivative financial instruments is to hedge non-functional currency risks and to guarantee a minimum fixed price in local currency. Our accounting policies for derivative financial instruments are based on the criteria for designation of a hedging transaction as an accounting hedge, either as a cash flow or fair value hedge. A cash flow hedge refers to the hedge of the exposure to variability in the cash flows of an asset or a liability, or of a forecasted transaction. A fair value hedge refers to the hedge of the exposure to changes in fair value of an asset or a liability, or of an unrecognized firm commitment. The criteria for designating a derivative as a hedge include the instrument's effectiveness in risk reduction and, in most cases, a one-to-one matching of the derivative instrument to its underlying transaction. Gains and losses from derivatives designated as fair value accounting hedges generally offset changes in the values of the hedged assets or liabilities over the life of the hedge. We recognize gains and losses on derivatives that are not currently designated as hedges for accounting purposes in earnings in other income, net. As of September 30, 2013, we had no derivative instruments designated as accounting hedges. As such, all gains and losses on derivatives for the three and nine months ended September 30, 2013 were recognized in earnings.
Revenue Recognition	'
	Revenue Recognition
	Our net revenues are generated principally by sales of our semiconductor solutions products. During the three and nine months ended September 30, 2013 and 2012, product net revenues represented more than 99% of our total net revenues.
	We recognize product revenues when the following fundamental criteria are met: (i) persuasive evidence of an arrangement exists, (ii) delivery has occurred or services have been rendered, (iii) the price to the customer is fixed or determinable and (iv) collection of the resulting receivable is reasonably assured. These criteria are usually met at the time of product shipment; however, we do not recognize revenue until all substantive customer acceptance requirements have been met, when applicable.
	A portion of our sales are made through distributors, agents or customers acting as agents under agreements allowing for rights of return or other potential concessions. Net revenues on sales made through these distributors are not recognized until the distributors ship the product to their customers.
	Revenues derived from billing customers for shipping and handling costs are classified as a component of net revenues. Costs of shipping and handling charged by suppliers are classified as a component of cost of net revenues.
	We record reductions to net revenues for estimated product returns and pricing adjustments, such as competitive pricing programs, in the same period that the related revenue is recorded. The amount of these reductions is based on historical sales returns and historical participation in pricing programs and other factors known at the time. If actual returns or actual participation in pricing programs differ significantly from our estimates, such differences would be recorded in our results of operations for the period in which the actual returns become known or pricing programs terminate. To date, changes in estimated returns have not been material to net revenues in any related period.
	We are party to an inventory “hubbing” agreement with Motorola Mobility, Inc. (formerly Motorola, Inc.), or Motorola. Pursuant to this agreement, we deliver products to the designated third-party warehouse based upon Motorola's projected needs, but do not recognize product revenue unless and until Motorola removes our products from the third-party warehouse to incorporate into its own products.
	We have entered into agreements to license certain hardware and software, also referred to as the “nodes,” to certain members of the Multimedia over Coax Alliance, or MoCA, for a period of three years and to provide upgrades when and if they become available. The agreements limit the rights to use the nodes to test compliance of the members' own products to the MoCA specification. For these arrangements, we defer all of the license revenues when the nodes are delivered and recognize the revenues on a straight-line basis over the three-year term of the agreement. To date, revenues under these arrangements have not been material.
	We provide rebates on our products to certain customers. At the time of the sale, we accrue 100% of the potential rebate as a reduction to net revenue and, based on our historical experience rate, do not apply a breakage factor. The amount of these reductions is based upon the terms included in various rebate agreements. We reverse the accrual for unclaimed rebate amounts as specific rebate programs contractually end or when we believe unclaimed rebates are no longer subject to payment and will not be paid. For the three months ended September 30, 2013 and 2012 and the nine months ended September 30, 2013 and 2012, we reduced net revenue by $1.3 million, $0.2 million, $1.9 million and $0.4 million, respectively, in connection with our rebate programs.
Concentration of Credit Risk	'
	Concentration of Credit Risk
	Financial instruments that potentially subject us to concentration of credit risk consist primarily of cash and cash equivalents, marketable securities, accounts receivable and leases payable. Our policy is to place our cash, cash equivalents and marketable securities with high quality financial institutions in order to limit our credit exposure. We extend credit to certain of our customers based on an evaluation of the customer's financial condition and a cash deposit is generally not required. We estimate potential losses on trade receivables on an ongoing basis.
	We maintain cash and cash equivalent accounts with Federal Deposit Insurance Corporation, or FDIC, insured financial institutions. In addition, certain of the our interest bearing collateral money market and savings accounts are each insured up to $250,000 by the FDIC. Our exposure for amounts in excess of FDIC insured limits at September 30, 2013 was $20.6 million. We have not experienced any losses in such accounts.
	We invest cash in deposits and money market funds with major financial institutions, U.S. government obligations and debt securities of corporations with investment grade credit ratings in a variety of industries. It is our policy to invest in instruments that have a final maturity of no longer than two years, and to maintain a portfolio weighted average maturity of no longer than 12 months.
Concentration of Supplier Risk	'
	Concentration of Supplier Risk
	We are dependent on NXP Semiconductors Netherlands B.V., or NXP, as our sole source manufacturer for some of our set-top-box, or STB, system-on-a-chip, or SoC, products and certain other products. If NXP became unable to manufacture these products for us in a timely manner and we were unable to find alternative vendors, our business, operating results and financial condition could be materially adversely affected. We are currently transitioning the manufacturing of certain STB SoC products to our other third-party manufacturers.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents
	Cash and cash equivalents consist of cash, money market funds and commercial paper. We consider all highly liquid investments with a maturity of three months or less from the date of purchase that are readily convertible into cash to be cash equivalents.
Deferred Compensation	'
	Deferred Compensation
	In June 2011, we implemented a non-qualified deferred compensation plan that permits certain key employees to defer portions of their compensation, subject to annual deferral limits, and have it credited to one or more investment options in the plan. At September 30, 2013, we had marketable securities totaling $0.4 million related to investments in equity securities that are held in a rabbi trust under our non-qualified deferred compensation plan. The total related deferred compensation liability was $0.4 million at September 30, 2013, all of which was classified as non-current liabilities and is recorded in the unaudited condensed consolidated balance sheets under other long-term liabilities.
Marketable Securities	'
	Marketable Securities
	We account for marketable securities by determining the appropriate classification of such securities at the time of purchase and reevaluating such classification as of each balance sheet date. As of September 30, 2013, we had classified $0.5 million of bank and time deposits and $0.4 million held under our non-qualified deferred compensation plan as trading securities. Trading securities are bought and held principally for the purpose of selling in the near term and are reported at fair value, with unrealized gains and losses included in earnings. All other marketable securities were classified as available-for-sale. Cash equivalents and available-for-sale marketable securities are reported at fair value with the related unrealized gains and losses included in accumulated other comprehensive income, a component of stockholders' equity, net of tax. The investments are adjusted for amortization of premiums and discounts to maturity and such amortization is included in interest income. Realized gains and losses and declines in value judged to be other than temporary are determined based on the specific identification method and are reported in the unaudited condensed consolidated statements of operations.
Fair Value of Financial Instruments	'
	Fair Value of Financial Instruments
	The carrying amounts of cash equivalents, marketable securities, trade receivables, accounts payable and other accrued liabilities approximate fair value due to their relative short-term maturities. The fair value of marketable securities was determined using the quoted market price for those securities. The carrying amounts of our capital lease obligations and other long-term liabilities approximate their fair value. The fair value of capital lease obligations was estimated based on the current interest rates available to us for debt instruments with similar terms, degrees of risk and remaining maturities.
Allowance for Doubtful Accounts	'
	Allowance for Doubtful Accounts
	We evaluate the collectability of accounts receivable based on a combination of factors. In cases where we are aware of circumstances that may impair a specific customer's ability to meet its financial obligations subsequent to the original sale, we will record a specific allowance against amounts due, and thereby reduce the net recognized receivable to the amount we reasonably believe will be collected. For all other customers, we recognize allowances for doubtful accounts based upon specific identification, industry and geographic concentrations, the current business environment and our historical experience. We recorded no allowance for doubtful accounts as of September 30, 2013 and December 31, 2012.
Inventories	'
	Inventories
	Inventories are stated at the lower of cost (first-in, first-out) or market. Lower of cost or market adjustments reduce the carrying value of the related inventory and take into consideration reductions in sales prices, excess inventory levels and obsolete inventory. These adjustments are calculated on a part-by-part basis and, in general, represent excess inventory value on hand compared to 12-month demand projections. Once established, these adjustments are considered permanent and are not reversed until the related inventory is sold or disposed.
	We make estimates about future customer demand for our products when establishing the appropriate reserve for excess and obsolete inventory. We write down inventory that has become obsolete or unmarketable by an amount equal to the difference between the cost of inventory and the estimated market value based on assumptions about future demand and market conditions. Inventory write downs are a component of our product cost of goods sold. For the three months ended September 30, 2013 and 2012 and the nine months ended September 30, 2013 and 2012, we recorded charges for excess and obsolete inventory of $2.6 million, $8,000, $3.5 million and $0.4 million, respectively.
Property and Equipment	'
	Property and Equipment
	Property and equipment are stated at cost and are depreciated using the straight-line method over the estimated useful lives of the assets (three to seven years), except leasehold improvements and software which are amortized over the lesser of the estimated useful lives of the asset or the remaining lease/license term.
Goodwill and Intangible Assets	'
	Goodwill and Intangible Assets
	We record goodwill and other intangible assets based on the fair value of the assets acquired. In determining the fair value of the assets acquired, we utilize extensive accounting estimates and judgments to allocate the purchase price to the fair value of the net tangible and intangible assets acquired. We use the discounted cash flow method to estimate the value of intangible assets acquired. The estimates used to value and amortize intangible assets are consistent with the plans and estimates that we use to manage our business and are based on available historical information and industry estimates and averages.
	We assess goodwill and intangible assets for impairment using fair value measurement techniques on an annual basis during the fourth quarter of the year, or more frequently if indicators of impairment exist. We perform an interim goodwill impairment test when it is more likely than not that the fair value of a reporting unit is less than the carrying amount. We operate as one reporting unit. The goodwill impairment test is a two step process. The first step compares the reporting unit's fair value to its net book value. If the fair value is less than the book value, the second step of the test compares the implied fair value of the reporting unit's goodwill with the carrying amount of that goodwill. If the carrying amount of goodwill exceeds its implied fair value, we would recognize an impairment loss equal to that excess amount. Determining the fair value of the implied goodwill is judgmental in nature and often involves the use of significant estimates and assumptions. These estimates and assumptions could have a significant impact on whether or not an impairment charge is recognized and also the magnitude of any such charge. Estimates of fair value are primarily determined using discounted cash flows and market comparisons. These approaches use significant estimates and assumptions, including the size and timing of deployments by our customers and related projections and timing of future cash flows, discount rates reflecting the risk inherent in future cash flows, perpetual growth rates, stage of products in development, determination of appropriate market comparables, and determination of whether a premium or discount should be applied to comparables.
Investment in a Privately Held Company	'
	Investment in a Privately Held Company
	Through the second quarter of 2013, we had accounted for our investment in a privately held company under the equity method of accounting since we had exercised significant influence, but we did not have the elements of control that would require consolidation. The rights of the other investors were both protective and participating. Unless we were determined to be the primary beneficiary, these rights precluded us from consolidating the investment. The investment was recorded initially at cost as an investment in a privately held company, and subsequently was adjusted for equity in net income and cash contributions and distributions. As described in Note 2, during the nine months ended September 30, 2013, we recorded an impairment charge of $4.8 million relating to our investment. As of September 30, 2013, our investment in the privately held company was $0.
Warranty Accrual	'
	Warranty Accrual
	We generally provide a warranty on our products for a period of one year; however, it may be longer for certain customers. Accordingly, we establish provisions for estimated product warranty costs at the time revenue is recognized based upon our historical activity and, additionally, for any known product warranty issues. Warranty provisions are recorded as a cost of net revenues. The determination of such provisions requires us to make estimates of product return rates and expected costs to replace or rework the products under warranty. When the actual product failure rates, cost of replacements and rework costs differ from our estimates, revisions to the estimated warranty accrual are made. Actual claims are charged against the warranty reserve.
Guarantees and Indemnifications	'
	Guarantees and Indemnifications
	In the ordinary course of business, we have entered into agreements with customers that include indemnity provisions. To date, there have been no known events or circumstances that have resulted in any significant costs related to these indemnification provisions and, as a result, no liabilities have been recorded in the accompanying financial statements.
Software Development Costs	'
	Software Development Costs
	Software development costs are capitalized beginning when technological feasibility has been established and ending when a product is available for sale to customers. To date, the period between achieving technological feasibility and when the software is made available for sale to customers has been relatively short and software development costs qualifying for capitalization have not been significant. As such, all software development costs have been expensed as incurred in research and development expense.
Stock-Based Compensation	'
	Stock-Based Compensation
	We have equity incentive plans under which incentive stock options have been granted to employees and restricted stock units and non-qualified stock options have been granted to employees and non-employees. We also have an employee stock purchase plan for all eligible employees.
	Our stock-based compensation cost is measured at the grant date, based on the estimated fair value of the award using either the Black-Scholes option pricing model for stock options or the grant date fair value of the stock on the date of the grant for restricted stock units, and is recognized as an expense over the employee's requisite service period. We have historically not granted performance based equity awards. However, in July 2013, we granted performance based equity awards which vest over a 15 month period, or earlier upon the achievement of certain milestones (see Note 3). The stock-based compensation expense attributable to awards under our 2007 Employee Stock Purchase Plan, or ESPP, was determined using the Black-Scholes option pricing model.
	We also grant awards to non-employees and determine the fair value of such stock-based compensation awards granted as either the fair value of the consideration received or the fair value of the equity instruments issued, whichever is more reliably measurable. If the fair value of the equity instruments issued is used, it is measured using the stock price and other measurement assumptions as of the earlier of (i) the date at which a commitment for performance by the counterparty to earn the equity instruments is reached, or (ii) the date at which the counterparty's performance is completed.
	We recognize excess tax benefits associated with stock-based compensation to stockholders' equity only when realized. When assessing whether excess tax benefits relating to stock-based compensation have been realized, we follow the “with and without” approach excluding any indirect effects to be realized until after the utilization of all other tax benefits available to us.
Income Taxes	'
	Income Taxes
	We estimate income taxes based on the various jurisdictions where we conduct business. Significant judgment is required in determining our worldwide income tax provision. We estimate the current tax liability and assess temporary differences that result from differing treatments of certain items for tax and accounting purposes. These differences result in deferred tax assets and liabilities, which are reflected in our balance sheets. We then assess the likelihood that deferred tax assets will be realized. A valuation allowance is recorded when it is more likely than not that some of the deferred tax assets will not be realized. When a valuation allowance is established or increased, we record a corresponding tax expense in our statements of operations. When a valuation allowance is decreased, we record the corresponding tax benefit in our statements of operations. We review the need for a valuation allowance each interim period to reflect uncertainties about whether we will be able to utilize deferred tax assets before they expire. The valuation allowance analysis is based on estimates of taxable income for the jurisdictions in which we operate and the periods over which our deferred tax assets will be realizable.
	We recognize and measure benefits for uncertain tax positions using a two-step approach. The first step is to evaluate the tax position taken or expected to be taken in a tax return by determining if the weight of available evidence indicates that it is more likely than not that the tax position will be sustained upon audit, including resolution of any related appeals or litigation processes. For tax positions that are more likely than not of being sustained upon audit, the second step is to measure the tax benefit as the largest amount that has more than a 50% chance of being realized upon settlement. Significant judgment is required to evaluate uncertain tax positions. We evaluate uncertain tax positions on a quarterly basis. The evaluations are based upon a number of factors, including changes in facts or circumstances, changes in tax law, correspondence with tax authorities during the course of audits and effective settlement of audit issues.
Segment Reporting	'
	Segment Reporting
	We are organized as, and operate in, one reportable segment: the design, development and sale of silicon integrated circuits. Products within this segment are embedded in electronic devices used to enable the delivery of multiple streams of high-definition, or HD, video and other multimedia content for entertainment purposes into and throughout the home. Our chief operating decision maker is our chief executive officer, or CEO. Our CEO reviews financial information presented on a consolidated basis for the purpose of evaluating financial performance and allocating resources. There are no segment managers who are held accountable for operations below the consolidated financial statement level. Our assets are primarily located in the United States and not allocated to any specific region. Therefore, geographic information is presented only for total revenue.
Recently Issued Accounting Standards	'
	Recently Issued Accounting Standards
	In February 2013, the Financial Accounting Standards Board (FASB) issued FASB Accounting Standards Update (ASU) No. 2013-02, Comprehensive Income (Topic 220) — Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. ASU 2013-02 requires an entity to provide information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, an entity is required to present, either on the face of the financial statements or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income, but only if the amount reclassified is required under GAAP to be reclassified to net income in its entirety in the same reporting period. For amounts that are not required to be reclassified in their entirety to net income, an entity is required to cross-reference to other disclosures that provide additional details about those amounts. ASU 2013-02 is effective prospectively for reporting periods beginning after December 15, 2012. The adoption of this ASU did not have a material impact on our financial statements.
	In July 2013, the FASB issued ASU No. 2013-11, Income Taxes (Topic 740), Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carry forward, a Similar Tax Loss, or a Tax Credit Carry forward Exists (a consensus of the FASB Emerging Issues Task Force). The amendments in this ASU state that an unrecognized tax benefit, or a portion of an unrecognized tax benefit, should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carry forward, a similar tax loss, or a tax credit carry forward, subject to certain exceptions, in which case such an unrecognized tax benefit should be presented in the financial statements as a liability. The amendments in this ASU are effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. We do not expect the adoption of this update to ASC 740 to have a material impact on our financial position, results of operations or cash flows.
	There have been no other recent accounting standards, or changes in accounting standards, during the nine months ended September 30, 2013, as compared to the recent accounting standards described in the Annual Report, that are of material significance, or have potential material significance, to us.

Supplemental_Financial_Informa1

Supplemental Financial Information (Tables)	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Summary of Contractual Maturities of Available-for-Sale Securities	'
	The following table summarizes the contractual maturities of our available-for-sale securities (in thousands):
		As of September 30,
		2013
	Less than one year	$	58,689
	Due in one to five years	73,894
	Due after five years	—
		$	132,583
Schedule of Fair Value of Financial Assets	'
	The fair value measurements of our cash equivalents, marketable securities, contingent consideration and non-qualified deferred compensation plan consisted of the following as of September 30, 2013 and December 31, 2012 (in thousands):
		Fair Value Measurements as of September 30, 2013
		Total				Level 1				Level 2			Level 3
	Assets:
	Cash equivalents	$	14,308			$	14,308			$	—		$	—
	Short-term investments:
	Commercial paper	4,494				—				4,494			—
	Corporate notes/bonds	54,195				—				54,195			—
	Mutual funds	407				407				—			—
	Bank and time deposits	453				453				—			—
	Long-term investments:
	Corporate notes/bonds	71,893				—				71,893			—
	U.S. treasury and agency notes/bonds	2,001				—				2,001			—
	Total assets at fair value	$	147,751			$	15,168			$	132,583		$	—
	Liabilities:
	Employee stock-based compensation guarantees	$	28			$	—			$	—		$	28
	Non-qualified deferred compensation plan	407				407				—			—
	Total liabilities at fair value	$	435			$	407			$	—		$	28
		Fair Value Measurements as of December 31, 2012
		Total				Level 1				Level 2			Level 3
	Assets:
	Cash equivalents	$	2,083			$	2,083			$	—		$	—
	Short-term investments:
	Commercial paper	6,998				—				6,998			—
	Corporate notes/bonds	67,990				—				67,990			—
	U.S. treasury and agency notes/bonds	3,005				—				3,005			—
	State and municipal bonds	1,238				—				1,238			—
	Mutual funds	368				368				—			—
	Bank and time deposits	382				382				—			—
	Long-term investments:
	Corporate notes/bonds	71,748				—				71,748			—
	Total assets at fair value	$	153,812			$	2,833			$	150,979		$	—
	Liabilities:
	Acquisition related contingent consideration	$	131			$	—			$	—		$	131
	Employee stock-based compensation guarantees	152				—				—			152
	Non-qualified deferred compensation plan	368				368				—			—
	Total liabilities at fair value	$	651			$	368			$	—		$	283
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation	'
	The following table represents the change in level 3 liabilities which relate to acquisition related contingent consideration and employee stock compensation guarantees (in thousands):
		Fair Value Measurement Using Significant Unobservable Inputs (Level 3)
		Acquisition related contingent consideration				Employee stock-based compensation guarantees				Total
	Liability as of December 31, 2012	$	131			$	152			$	283
	Adjustments to fair value	(131		)		—				(131		)
	Decrease in compensation expense	—				(124		)		(124		)
	Liability as of September 30, 2013	$	—			$	28			$	28
Schedule of Inventory	'
	The components of inventory were as follows (in thousands):
		September 30, 2013				December 31, 2012
	Work in process	$	8,061			$	16,353
	Finished goods	7,055				10,042
	Total inventory	$	15,116			$	26,395
Summary of Available-for-Sale Securities	'
	The following tables summarize available-for-sale investments by security type as of September 30, 2013 and December 31, 2012 (in thousands):
		As of September 30, 2013
		Cost				Gross				Gross			Fair Market
						Unrealized				Unrealized			Value
						Gains				Losses
	Available-for-sale securities:
	Commercial paper	$	4,495			$	—			$	(1	)	$	4,494
	Corporate notes/bonds	54,100				95				—			54,195
	Total marketable securities, short-term	58,595				95				(1		)	58,689
	Corporate notes/bonds, long-term	71,961				21				(89		)	71,893
	U.S. treasury and agency notes/bonds, long-term	2,000				1				—			2,001
	Total	$	132,556			$	117			$	(90	)	$	132,583
		As of December 31, 2012
		Cost				Gross				Gross			Fair Market
						Unrealized				Unrealized			Value
						Gains				Losses
	Available-for-sale securities:
	Commercial paper	$	6,988			$	11			$	(1	)	$	6,998
	Corporate notes/bonds	67,944				56				(10		)	67,990
	U.S. treasury and agency notes/bonds	3,000				5				—			3,005
	State and municipal bonds	1,235				3				—			1,238
	Total marketable securities, short-term	79,167				75				(11		)	79,231
	Corporate notes/bonds, long-term	71,648				146				(46		)	71,748
	Total	$	150,815			$	221			$	(57	)	$	150,979
Schedule of Property and Equipment	'
	Property and equipment consisted of the following (in thousands, except for years):
		Useful Lives		September 30, 2013				December 31, 2012
		(in years)
	Office and laboratory equipment	5		$	23,430			$	20,629
	Computer equipment	5-Mar		7,617				6,473
	Furniture and fixtures	7-Mar		2,193				2,032
	Leasehold improvements	Lease term		7,090				6,438
	Software	3-Jan		4,663				2,913
	Construction in progress			253				846
				45,246				39,331
	Accumulated depreciation			(27,318		)		(21,702		)
	Property and equipment, net			$	17,928			$	17,629
Components of Intangible Assets	'
	Intangible assets consisted of the following (in thousands):
			As of September 30, 2013
			Gross				Accumulated Amortization				Net
	Developed technology		$	43,475			$	(12,709	)		$	30,766
	In-process research and development		13,761				—				13,761
	Total intangibles amortized to cost of net revenues		57,236				(12,709		)		44,527
	Customer relationships		6,800				(1,336		)		5,464
	Non-compete agreement		1,603				(1,107		)		496
	Customer backlog		2,000				(2,000		)		—
	Total intangibles amortized to operating expense		10,403				(4,443		)		5,960
	Total intangible assets		$	67,639			$	(17,152	)		$	50,487
Schedule of Accrued Warranty	'
	The following table presents a roll forward of our product warranty liability, which is included within accrued expenses and other current liabilities in the unaudited condensed consolidated balance sheets (in thousands):
		Nine Months Ended September 30,
		2013
	Beginning balance	$	448
	Accruals for warranties issued during the period	134
	Settlements made during the period	(21		)
	Change in estimated warranty rate	(445		)
	Expirations	(32		)
	Ending balance	$	84
Schedule of Restructuring Activity	'
	The following table presents a roll forward of our restructuring liability as of September 30, 2013, which is included within accrued payroll and benefits in the unaudited condensed consolidated balance sheets (in thousands):
			Restructuring Liability - Employee Separation Expenses
	Liability as of January 1, 2012		$	—
	Restructuring charges		897
	Cash payments		(363		)
	Liability as of December 31, 2012		534
	Restructuring charges		1,694
	Cash payments		(1,985		)
	Liability as of September 30, 2013		$	243
Schedule of Allocation of Stock-Based Compensation Expense	'
	We allocated stock-based compensation expense as follows (in thousands):
		Three Months Ended September 30,								Nine Months Ended September 30,
		2013				2012				2013			2012
	Cost of net revenues	$	227			$	217			$	658		$	567
	Research and development	2,766				2,030				6,730			5,554
	Sales and marketing	510				675				1,324			1,679
	General and administrative	1,089				1,283				3,109			3,182
	Total stock-based compensation expense	$	4,592			$	4,205			$	11,821		$	10,982
Schedule of Share-Based Payment Award, Assumptions	'
	The fair value of stock options granted to employees, directors and consultants was estimated at the grant date using the following assumptions:
		Three Months Ended September 30,						Nine Months Ended September 30,
		2013			2012			2013		2012
	Expected life (years)	5.4			5.2			5.3 - 5.4		5.1 - 5.2
	Contractual term (years)	10			10			10		10
	Risk-free interest rate	1.52	%		0.76	%		0.79% - 1.52%		0.76% - 1.09%
	Expected volatility	89	%		90	%		89% - 90%		89% - 90%
	Expected dividend yield	—			—			—		—
Schedule of Share-Based Payment Award under ESPP, Assumptions	'
	For the three and nine months ended September 30, 2013 and 2012 the fair value of expected shares to be issued under the ESPP were estimated using the following assumptions:
		Three Months Ended September 30,				Nine Months Ended September 30,
		2013		2012		2013		2012
	Expected life (years)	0.5 to 1.0		0.5 to 1.0		0.5 to 1.0		0.5 to 1.0
	Risk-free interest rate	0.08% to 0.18%		0.13% to 0.19%		0.08% to 0.19%		0.05% to 0.22%
	Expected volatility	47% to 63%		64% to 84%		47% to 84%		58% to 100%
	Expected dividend yield	—		—		—		—

Business_Combinations_Tables

Business Combinations (Tables)	9 Months Ended
	Sep. 30, 2013
Mobius [Member]	'
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	'
	On the acquisition date, based on preliminary estimates of fair value, we allocated the total consideration to the following assets (in thousands):
		Allocation of
		Purchase Price
	Intangible assets	$	12,239
	Goodwill	752
	Prepaid expenses	25
	Property and equipment, net	9
	Total purchase price	$	13,025
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination	'
	The allocation of the purchase price to the net assets acquired and liabilities assumed resulted in the recognition of the following intangible assets (in thousands, except for years):
						Estimated Useful
		Amount				Life (in years)
	In-process research and development	$	12,136			*
	Non-compete agreement	103				2
	Total intangible assets	$	12,239
	*Upon completion of each project, the related in-process research and development, or IPR&D, asset will be amortized over its estimated useful life. If any of the projects are abandoned or the forecast of the project indicates that the fair value is less than the carrying amount, we will be required to write down the related IPR&D asset.
PLX Technology, Inc., [Member]	'
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	'
	On the acquisition date, we allocated the total consideration to the following assets (in thousands):
			Allocation of
			Purchase Price
	Property and equipment, net		$	241
	Intangible assets		9,200
	Goodwill		652
	Employee compensation liabilities		(119		)
	Total purchase price		$	9,974
Business Acquisition Cost of Acquired Entity Table	'
	The total acquisition date fair value of the consideration was estimated at $10.0 million as follows (in thousands):
	Initial cash payment to PLX		$	6,874
	Estimated fair value of contingent milestone consideration		3,100
	Total purchase price		$	9,974
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination	'
	The allocation of the purchase price to the net assets acquired and liabilities assumed resulted in the recognition of the following intangible assets (in thousands, except for years):
							Estimated Useful
			Amount				Life (in years)
	In-process research and development		$	6,200			*
	Customer relationships		2,900				7
	Non-compete agreement		100				2
	Total intangible assets		$	9,200
	*Upon completion of each project, the related IPR&D asset will be amortized over its estimated useful life. If any of the projects are abandoned or the forecast of the project indicates that the fair value is less than the carrying amount, we will be required to write down the related IPR&D asset.
STB Business [Member]	'
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	'
	The allocation of the purchase price to the assets acquired and liabilities assumed was as follows (in thousands):
			Allocation of
			Purchase Price
	Accounts receivable		$	8,066
	Prepaid inventory		4,310
	Inventories		7,091
	Prepaid expenses and other assets		4,966
	Property and equipment, net		2,433
	Other long term assets		125
	Intangible assets		46,200
	Goodwill		3,285
	Employee compensation liabilities		(2,342		)
	Total purchase price		$	74,134
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination	'
	The allocation of the purchase price to the net assets acquired and liabilities assumed resulted in the recognition of the following intangible assets (in thousands, except for years):
							Estimated Useful
			Amount				Life (in years)
	Developed technology		$	32,400			4
	In-process research and development		6,500				*
	Customer relationships		3,900				7
	Non-compete agreement		1,400				2
	Customer backlog		2,000				1
	Total intangible assets		$	46,200
Supplemental Unaudited Pro Forma Net Sales and Net Income of Combined Entity	'
	The following unaudited pro forma information presents the consolidated results of operations of Entropic and Trident as if the acquisition had occurred at the beginning of the period presented, with pro forma adjustments to give effect to amortization of intangible assets and certain other adjustments (in thousands, except per share amounts):
		Three Months Ended September 30,				Nine Months Ended September 30,
		2012				2012
	Net revenues	$	89,825			$	254,697
	Net income (loss)	527				(2,870		)
	Net income (loss) per share - basic and diluted	0.01				(0.03		)
Supplemental Pro Forma Combined Results of Operations	'
	Adjustments to the supplemental pro forma combined results of operations were as follows (in thousands):
		Three Months Ended September 30,				Nine Months Ended September 30,
		2012				2012
	Net impact of the change in amortization of intangibles	$	—			$	(733	)
	Transaction related expenses related to acquisition	183				4,484
	Reorganization expenses related to Trident's bankruptcy filing	—				1,471
	Adjust taxes to the blended rate after business combination	(64		)		3,954
		$	119			$	9,176

Net_Loss_Income_Per_Common_Sha1

Net (Loss) Income Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Schedule of Computation of Basic and Diluted Net Income Per Share	'
	The following table sets forth the computation of basic and diluted net (loss) income per share for the periods indicated (in thousands, except per share data):
		Three Months Ended September 30,					Nine Months Ended September 30,
		2013			2012		2013			2012
	Numerator:
	Net (loss) income—basic and diluted	$	(11,935	)	$	408	$	(54,252	)	$	4,474
	Denominator:
	Weighted average number of shares of common stock outstanding—basic	91,069			88,399		90,225			87,913
	Effect of dilutive securities:
	ESPP shares	—			97		—			75
	Stock award common share equivalents	—			2,389		—			1,930
	Weighted average number of shares of common stock outstanding—diluted	91,069			90,885		90,225			89,918
	Net (loss) income per share—basic	$	(0.13	)	$	—	$	(0.60	)	$	0.05
	Net (loss) income per share—diluted	$	(0.13	)	$	—	$	(0.60	)	$	0.05

Significant_Customer_and_Geogr1

Significant Customer and Geographic Information (Tables)	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Schedule of Total Net Revenues or Accounts Receivable from Customers Exceeding 10% of Total	'
	Based on direct shipments, customers that exceeded 10% of total net revenues or accounts receivable were as follows:
		Net Revenues					Net Revenues					Accounts Receivable
		Three Months Ended September 30,					Nine Months Ended September 30,					As of September 30,		As of December 31,
		2013		2012			2013			2012		2013		2012
	Foxconn Electronics, Inc.	23	%	*			17	%		*		22	%	*
	Motorola Mobility, Inc.	*		12	%		*			13	%	*		11	%
	Wistron NeWeb Corporation	21	%	20	%		17	%		22	%	23	%	29	%
	*	Customer accounted for less than 10% of total net revenues or accounts receivable, as applicable, for the period indicated.
Schedule of Net Revenues Allocated to Geographic Region	'
	Net revenues are allocated to the geographic region based on the shipping destination of customer orders. Net revenues by geographic region were as follows (in thousands):
		Three Months Ended September 30,							Nine Months Ended September 30,
		2013			2012				2013			2012
	Asia	$	44,620		$	81,102			$	171,384		$	204,109
	Europe	686			1,787				2,927			5,036
	United States	2,246			1,378				5,644			2,388
	North America, other	8,824			5,558				21,490			20,447
	Total	$	56,376		$	89,825			$	201,445		$	231,980

Organization_and_Summary_of_Si2

Organization and Summary of Significant Accounting Policies (Narrative) (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Organization And Significant Accounting Policies [Line Items]	'	'	'	'
Hardware and software license duration, years	'	'	'3 years	'
Reductions in net revenue in connection with rebate programs	$1,300,000	$200,000	$1,900,000	$400,000
Cash, Uninsured Amount	20,600,000	'	20,600,000	'
Maturity of financial instruments, maximum (years)	'	'	'2 years	'
Deferred Compensation Plan Assets	400,000	'	400,000	'
Deferred compensation liability classified as non-current liabilities	400,000	'	400,000	'
Provision for excess and obsolete inventory	2,600,000	8,000	3,492,000	365,000
Impairment of investment	0	0	4,780,000	0
Investment in a privately held company	0	'	0	'
Product warranty period (years)	'	'	'1 year	'
Minimum [Member]	'	'	'	'
Organization And Significant Accounting Policies [Line Items]	'	'	'	'
Useful lives of property and equipment	'	'	'3 years	'
Maximum [Member]	'	'	'	'
Organization And Significant Accounting Policies [Line Items]	'	'	'	'
Weighted average maturity of financial instruments (months)	'	'	'12 months	'
Useful lives of property and equipment	'	'	'7 years	'
Bank And Time Deposits [Member]	'	'	'	'
Organization And Significant Accounting Policies [Line Items]	'	'	'	'
Trading Securities	500,000	'	500,000	'
Non-Qualified Deferred Compensation Plan [Member]	'	'	'	'
Organization And Significant Accounting Policies [Line Items]	'	'	'	'
Trading Securities	$400,000	'	$400,000	'
Sales Revenue, Goods, Net [Member]	'	'	'	'
Organization And Significant Accounting Policies [Line Items]	'	'	'	'
Percentage of product net revenues to total revenues	99.00%	99.00%	99.00%	99.00%

Supplemental_Financial_Informa2

Supplemental Financial Information (Narrative) (Detail) (USD $)

3 Months Ended

9 Months Ended

12 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

Share data in Millions, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Jun. 05, 2013

Jul. 06, 2012

Sep. 30, 2013

Apr. 12, 2012

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2011

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

employee

employee

Mobius [Member]

PLX Technology, Inc., [Member]

STB Business [Member]

STB Business [Member]

Zenverge Inc., [Member]

Zenverge Inc., [Member]

Zenverge Inc., [Member]

Zenverge Inc., [Member]

Consultant Equity Incentive Plans [Member]

Consultant Equity Incentive Plans [Member]

Consultant Equity Incentive Plans [Member]

Consultant Equity Incentive Plans [Member]

Employee Stock Option [Member]

Employee Stock Purchase Plan [Member]

Employee Stock Purchase Plan [Member]

Employee Stock Purchase Plan [Member]

Employee Stock Purchase Plan [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Minimum [Member]

Maximum [Member]

Bank And Time Deposits [Member]

Non-Qualified Deferred Compensation Plan [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Supplemental Financial Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Depreciation and amortization

$2,200,000

$1,400,000

$6,288,000

$3,937,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Trading Securities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

500,000

400,000

Net unrealized gains on trading securities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

57,000

Trading securities at cost

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

300,000

Realized gains on available-for-sale securities

41,000

2,000

50,000

13,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maturity of highly liquid money market securities, maximum, days

'

'

'90 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Impairment of investment

0

0

4,780,000

0

'

'

'

'

'

'

4,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Goodwill

4,688,000

'

4,688,000

'

4,664,000

[1]

752,000

652,000

3,300,000

3,285,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Goodwill, Preliminary

'

'

'

'

'

'

'

'

4,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Decrease in goodwill pertaining to acquired entity

'

'

'

'

'

'

'

700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Investment owned, at cost

'

'

'

'

'

'

'

'

'

'

'

'

10,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Equity interest

'

'

'

'

'

'

'

'

'

'

'

'

16.30%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Carrying value of investment in a privately held company

0

'

0

'

'

'

'

'

'

0

0

5,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Investment, Change in Carrying Value

'

'

'

'

'

'

'

'

'

0

5,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Management bonuses, accrued

0

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Restructuring charges

-69,000

0

1,694,000

0

897,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Reduction of personnel

'

'

66

'

40

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of reduction of workforce

'

'

10.00%

'

6.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred Compensation Plan Assets

400,000

'

400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred compensation liability classified as non-current liabilities

400,000

'

400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Inventory acquisition commitments

8,300,000

'

8,300,000

'

12,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

ESPP - rate of the lower fair market value of common stock on offering date or purchase date

'

'

85.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase offering period, months, maximum

'

'

'12 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock-based compensation expense

4,592,000

4,205,000

11,821,000

10,982,000

'

'

'

'

'

'

'

'

'

0

8,000

9,000

46,000

'

500,000

600,000

1,200,000

1,800,000

'

'

'

'

'

'

Unrecognized compensation costs, amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$33,200,000

$500,000

'

$500,000

'

'

'

'

'

'

'

Unrecognized compensation costs, period, in years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'1 year 4 months

'

'

'5 months

'

'

'

'

'

'

'

Stock options granted, shares

0.2

'

1.2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock options exercised, shares

0.1

'

0.6

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock options forfeited or expired, shares

0.3

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock options outstanding, shares

10.2

'

10.2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Restricted stock units vested

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.1

1.1

'

'

'

'

Restricted stock units outsanding

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6.8

6.8

'

'

'

'

Restricted stock units granted

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.5

5.4

'

'

'

'

Restricted stock units forfeited

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.3

0.7

'

'

'

'

Restricted stock units vesting period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'1 year

'4 years

'

'

[1]

(1) The unaudited condensed consolidated balance sheet at December 31, 2012 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

Supplemental_Financial_Informa3

Supplemental Financial Information (Summary of Available-for-Sale Securities) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	$132,556	$150,815
Available-for-sale Securities, Gross Unrealized Gain, Instant	117	221
Available-for-sale Securities, Gross Unrealized Loss, Instant	-90	-57
Fair Market Value	132,583	150,979
Short-Term Investments [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	58,595	79,167
Available-for-sale Securities, Gross Unrealized Gain, Instant	95	75
Available-for-sale Securities, Gross Unrealized Loss, Instant	-1	-11
Fair Market Value	58,689	79,231
Short-Term Investments [Member] | Commercial Paper [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	4,495	6,988
Available-for-sale Securities, Gross Unrealized Gain, Instant	0	11
Available-for-sale Securities, Gross Unrealized Loss, Instant	-1	-1
Fair Market Value	4,494	6,998
Short-Term Investments [Member] | Corporate Notes/Bonds [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	54,100	67,944
Available-for-sale Securities, Gross Unrealized Gain, Instant	95	56
Available-for-sale Securities, Gross Unrealized Loss, Instant	0	-10
Fair Market Value	54,195	67,990
Short-Term Investments [Member] | US States and Political Subdivisions Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	'	1,235
Available-for-sale Securities, Gross Unrealized Gain, Instant	'	3
Available-for-sale Securities, Gross Unrealized Loss, Instant	'	0
Fair Market Value	'	1,238
Short-Term Investments [Member] | U.S. Treasury And Agency Notes/Bonds [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	'	3,000
Available-for-sale Securities, Gross Unrealized Gain, Instant	'	5
Available-for-sale Securities, Gross Unrealized Loss, Instant	'	0
Fair Market Value	'	3,005
Long-Term Investments [Member] | Corporate Notes/Bonds [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	71,961	71,648
Available-for-sale Securities, Gross Unrealized Gain, Instant	21	146
Available-for-sale Securities, Gross Unrealized Loss, Instant	-89	-46
Fair Market Value	71,893	71,748
Long-Term Investments [Member] | U.S. Treasury And Agency Notes/Bonds [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	2,000	'
Available-for-sale Securities, Gross Unrealized Gain, Instant	1	'
Available-for-sale Securities, Gross Unrealized Loss, Instant	0	'
Fair Market Value	$2,001	'

Supplemental_Financial_Informa4

Supplemental Financial Information (Summary of Contractual Maturities of Available-for-Sale Securities) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Disclosure Supplemental Financial Information Summary Of Contractual Maturities Of Available For Sale Securities [Abstract]	'	'
Less than one year	$58,689	'
Due in one to five years	73,894	'
Due after five years	0	'
Fair Market Value	$132,583	$150,979

Supplemental_Financial_Informa5

Supplemental Financial Information (Schedule of Fair Value of Financial Assets) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash equivalents	$14,308	$2,083
Total assets at fair value	147,751	153,812
Total liabilities at fair value	435	651
Acquisition Related Contingent Consideration [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	'	131
Employee Stock Compensation Guarantees [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	28	152
Non-Qualified Deferred Compensation Plan [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	407	368
Commercial Paper [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	4,494	6,998
Corporate Notes/Bonds [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	54,195	67,990
Corporate Notes/Bonds [Member] | Long-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	71,893	71,748
US States and Political Subdivisions Debt Securities [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	'	1,238
Mutual Funds [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	407	368
Bank And Time Deposits [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	453	382
U.S. Treasury And Agency Notes/Bonds [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	'	3,005
U.S. Treasury And Agency Notes/Bonds [Member] | Long-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	2,001	'
Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash equivalents	14,308	2,083
Total assets at fair value	15,168	2,833
Total liabilities at fair value	407	368
Level 1 [Member] | Acquisition Related Contingent Consideration [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	'	0
Level 1 [Member] | Employee Stock Compensation Guarantees [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	0	0
Level 1 [Member] | Non-Qualified Deferred Compensation Plan [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	407	368
Level 1 [Member] | Commercial Paper [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	0	0
Level 1 [Member] | Corporate Notes/Bonds [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	0	0
Level 1 [Member] | Corporate Notes/Bonds [Member] | Long-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	0	0
Level 1 [Member] | US States and Political Subdivisions Debt Securities [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	'	0
Level 1 [Member] | Mutual Funds [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	407	368
Level 1 [Member] | Bank And Time Deposits [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	453	382
Level 1 [Member] | U.S. Treasury And Agency Notes/Bonds [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	'	0
Level 1 [Member] | U.S. Treasury And Agency Notes/Bonds [Member] | Long-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	0	'
Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash equivalents	0	0
Total assets at fair value	132,583	150,979
Total liabilities at fair value	0	0
Level 2 [Member] | Acquisition Related Contingent Consideration [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	'	0
Level 2 [Member] | Employee Stock Compensation Guarantees [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	0	0
Level 2 [Member] | Non-Qualified Deferred Compensation Plan [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	0	0
Level 2 [Member] | Commercial Paper [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	4,494	6,998
Level 2 [Member] | Corporate Notes/Bonds [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	54,195	67,990
Level 2 [Member] | Corporate Notes/Bonds [Member] | Long-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	71,893	71,748
Level 2 [Member] | US States and Political Subdivisions Debt Securities [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	'	1,238
Level 2 [Member] | Mutual Funds [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	0	0
Level 2 [Member] | Bank And Time Deposits [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	0	0
Level 2 [Member] | U.S. Treasury And Agency Notes/Bonds [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	'	3,005
Level 2 [Member] | U.S. Treasury And Agency Notes/Bonds [Member] | Long-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	2,001	'
Level 3 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash equivalents	0	0
Total assets at fair value	0	0
Total liabilities at fair value	28	283
Level 3 [Member] | Acquisition Related Contingent Consideration [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	'	131
Level 3 [Member] | Employee Stock Compensation Guarantees [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	28	152
Level 3 [Member] | Non-Qualified Deferred Compensation Plan [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	0	0
Level 3 [Member] | Commercial Paper [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	0	0
Level 3 [Member] | Corporate Notes/Bonds [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	0	0
Level 3 [Member] | Corporate Notes/Bonds [Member] | Long-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	0	0
Level 3 [Member] | US States and Political Subdivisions Debt Securities [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	'	0
Level 3 [Member] | Mutual Funds [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	0	0
Level 3 [Member] | Bank And Time Deposits [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	0	0
Level 3 [Member] | U.S. Treasury And Agency Notes/Bonds [Member] | Short-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	'	0
Level 3 [Member] | U.S. Treasury And Agency Notes/Bonds [Member] | Long-Term Investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Investments	$0	'

Supplemental_Financial_Informa6

Supplemental Financial Information (Schedule Of Change In Liability) (Detail) (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'
Liability as of December 31, 2012	$283
Adjustments to fair value	-131
Decrease in compensation expense	-124
Liability as of September 30, 2013	28
Acquisition Related Contingent Consideration [Member]	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'
Liability as of December 31, 2012	131
Adjustments to fair value	-131
Decrease in compensation expense	0
Liability as of September 30, 2013	0
Employee Stock Compensation Guarantees [Member]	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'
Liability as of December 31, 2012	152
Adjustments to fair value	0
Decrease in compensation expense	-124
Liability as of September 30, 2013	$28

Supplemental_Financial_Informa7

Supplemental Financial Information (Schedule of Inventory) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Disclosure Supplemental Financial Information Schedule Of Inventory [Abstract]	'	'
Work in process	$8,061	$16,353
Finished goods	7,055	10,042
Total inventory	$15,116	$26,395	[1]
[1]	(1) The unaudited condensed consolidated balance sheet at December 31, 2012 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

Supplemental_Financial_Informa8

Supplemental Financial Information (Schedule of Property and Equipment) (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	$45,246	$39,331
Accumulated depreciation	-27,318	-21,702
Property and equipment, net	17,928	17,629	[1]
Minimum [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Useful lives	'3 years	'
Maximum [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Useful lives	'7 years	'
Office And Laboratory Equipment [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Useful lives	'5 years	'
Property and equipment, gross	23,430	20,629
Computer Equipment [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	7,617	6,473
Computer Equipment [Member] | Minimum [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Useful lives	'3 years	'
Computer Equipment [Member] | Maximum [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Useful lives	'5 years	'
Furniture And Fixtures [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	2,193	2,032
Furniture And Fixtures [Member] | Minimum [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Useful lives	'3 years	'
Furniture And Fixtures [Member] | Maximum [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Useful lives	'7 years	'
Leasehold Improvements [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	7,090	6,438
Software [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	4,663	2,913
Software [Member] | Minimum [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Useful lives	'1 year	'
Software [Member] | Maximum [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Useful lives	'3 years	'
Construction in Progress [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	$253	$846
[1]	(1) The unaudited condensed consolidated balance sheet at December 31, 2012 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

Supplemental_Financial_Informa9

Supplemental Financial Information (Components of Intangible Assets) (Detail) (USD $)	Sep. 30, 2013
In Thousands, unless otherwise specified
Intangible Assets [Line Items]	'
Gross	$67,639
Accumulated Amortization	-17,152
Net	50,487
Intangibles Amortized To Cost Of Net Revenues [Member]	'
Intangible Assets [Line Items]	'
Gross	57,236
Accumulated Amortization	-12,709
Net	44,527
Intangibles Amortized To Cost Of Net Revenues [Member] | Developed Technology [Member]	'
Intangible Assets [Line Items]	'
Gross	43,475
Accumulated Amortization	-12,709
Net	30,766
Intangibles Amortized To Cost Of Net Revenues [Member] | In-Process Research And Development [Member]	'
Intangible Assets [Line Items]	'
Gross	13,761
Accumulated Amortization	0
Net	13,761
Intangibles Amortized To Operating Expense [Member]	'
Intangible Assets [Line Items]	'
Gross	10,403
Accumulated Amortization	-4,443
Net	5,960
Intangibles Amortized To Operating Expense [Member] | Customer Relationships [Member]	'
Intangible Assets [Line Items]	'
Gross	6,800
Accumulated Amortization	-1,336
Net	5,464
Intangibles Amortized To Operating Expense [Member] | Non-Compete Agreements [Member]	'
Intangible Assets [Line Items]	'
Gross	1,603
Accumulated Amortization	-1,107
Net	496
Intangibles Amortized To Operating Expense [Member] | Customer Backlog [Member]	'
Intangible Assets [Line Items]	'
Gross	2,000
Accumulated Amortization	-2,000
Net	$0

Recovered_Sheet1

Supplemental Financial Information (Schedule of Accrued Warranty) (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Movement in Standard Product Warranty Accrual [Roll Forward]	'
Beginning balance	$448
Accruals for warranties issued during the period	134
Settlements made during the period	-21
Change in estimated warranty rate	-445
Product Warranty Accrual Expirations Of Warranties	-32
Ending balance	$84

Recovered_Sheet2

Supplemental Financial Information (Schedule Of Restructuring Activity) (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Restructuring Liability - Employee Separation Expenses	'	'	'	'	'
Beginning Liability	'	'	$534	$0	$0
Restructuring charges	-69	0	1,694	0	897
Cash payments	'	'	-1,985	'	-363
Ending Liability	$243	'	$243	'	$534

Recovered_Sheet3

Supplemental Financial Information (Schedule of Allocation of Stock-Based Compensation Expense) (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation	$4,592,000	$4,205,000	$11,821,000	$10,982,000
Cost of net revenues	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation	227,000	217,000	658,000	567,000
Research and development	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation	2,766,000	2,030,000	6,730,000	5,554,000
Sales and marketing	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation	510,000	675,000	1,324,000	1,679,000
General and administrative	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation	$1,089,000	$1,283,000	$3,109,000	$3,182,000

Recovered_Sheet4

Supplemental Financial Information (Schedule of Share-Based Payment Award, Assumptions) (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Employee Options [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Expected life	'5 years 5 months	'5 years 2 months	'	'
Non-Employee Options [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Contractual term	'10 years	'10 years	'10 years	'10 years
Employee And Non-Employee Options [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Risk-free interest rate, minimum	'	'	0.79%	0.76%
Risk-free interest rate, maximum	'	'	1.52%	1.09%
Risk-free interest rate	1.52%	0.76%	'	'
Expected volatility	89.00%	90.00%	'	'
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Minimum [Member] | Employee Options [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Expected life	'	'	'5 years 4 months	'5 years 1 month
Minimum [Member] | Employee And Non-Employee Options [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Expected volatility	'	'	89.00%	89.00%
Maximum [Member] | Employee Options [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Expected life	'	'	'5 years 5 months	'5 years 2 months
Maximum [Member] | Employee And Non-Employee Options [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Expected volatility	'	'	90.00%	90.00%

Recovered_Sheet5

Supplemental Financial Information (Schedule of Share-Based Payment Award under ESPP, Assumptions) (Detail) (ESPP Shares [Member])	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Risk-free interest rate, minimum	0.08%	0.13%	0.08%	0.05%
Risk-free interest rate, maximum	0.18%	0.19%	0.19%	0.22%
Expected volatility, minimum	47.00%	64.00%	47.00%	58.00%
Expected volatility, maximum	63.00%	84.00%	84.00%	100.00%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Minimum [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Expected life	'6 months	'6 months	'6 months	'6 months
Maximum [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Expected life	'1 year	'1 year	'1 year	'1 year

Business_Combinations_Narrativ

Business Combinations (Narrative) (Detail) (USD $)

3 Months Ended

9 Months Ended

11 Months Ended

0 Months Ended

9 Months Ended

0 Months Ended

3 Months Ended

9 Months Ended

0 Months Ended

9 Months Ended

Share data in Millions, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Nov. 30, 2012

Dec. 31, 2012

Jul. 18, 2013

Jun. 05, 2013

Sep. 30, 2013

Sep. 30, 2012

Jul. 18, 2013

Jul. 18, 2013

Apr. 12, 2012

Mar. 31, 2013

Sep. 30, 2013

Sep. 30, 2012

Jul. 06, 2012

Sep. 30, 2013

Sep. 30, 2012

Mobius [Member]

Mobius [Member]

Mobius [Member]

Mobius [Member]

Mobius [Member]

Mobius [Member]

STB Business [Member]

STB Business [Member]

STB Business [Member]

STB Business [Member]

PLX Technology, Inc., [Member]

PLX Technology, Inc., [Member]

PLX Technology, Inc., [Member]

Fifteen Month [Member]

Thirty-Six Month [Member]

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Payments to Acquire Businesses, Net of Cash Acquired

'

'

'

'

'

'

'

$13,017,000

$0

'

'

'

'

$0

$69,490,000

'

$0

$6,874,000

Cash paid for acquired assets

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6,874,000

'

'

Restricted stock units granted to employees of acquired entity, shares

'

'

'

'

'

3.2

'

'

'

0.9

2.3

'

'

'

'

'

'

'

Restricted stock units granted to employees of acquired entity, fair value

'

'

'

'

'

14,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Restricted stock units vesting period

'

'

'

'

'

'

'

'

'

'15 months

'36 months

'

'

'

'

'

'

'

Weighted average cost of capital

'

'

'

'

'

'

21.00%

'

'

'

'

'

'

'

'

41.00%

'

'

Goodwill

4,688,000

4,688,000

'

'

4,664,000

[1]

'

752,000

'

'

'

'

3,285,000

'

3,300,000

'

652,000

'

'

Business Combination, Consideration Transferred

'

'

'

'

'

'

'

'

'

'

'

74,100,000

'

'

'

9,974,000

'

'

Total consideration net assets

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

11,900,000

'

'

Business combination potential additional consideration

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,000,000

'

'

Estimated fair value of contingent milestone consideration

'

'

'

3,500,000

'

'

'

'

'

'

'

'

'

'

'

3,100,000

'

'

Increase (Decrease) in acquisition related contingent consideration liability

-100,000

-131,000

230,000

400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Settlement of contingent consideration

'

'

'

3,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase price of working capital assets

'

'

'

'

'

'

'

'

'

'

'

24,400,000

'

'

'

'

'

'

Employee liabilities assumed on acquisition

'

'

'

'

'

'

'

'

'

'

'

2,342,000

'

'

'

119,000

'

'

Post-closing purchase price adjustment, reduction in purchase price

'

'

'

'

'

'

'

'

'

'

'

'

$700,000

'

'

'

'

'

[1]

(1) The unaudited condensed consolidated balance sheet at December 31, 2012 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

Business_Combinations_Business

Business Combinations (Business Acquisition Cost of Acquired Entity) (Detail) (USD $)	Nov. 30, 2012	Jul. 06, 2012
In Thousands, unless otherwise specified		PLX Technology, Inc., [Member]
Business Acquisition, Contingent Consideration [Line Items]	'	'
Initial cash payment to PLX	'	$6,874
Estimated fair value of contingent milestone consideration	3,500	3,100
Business Combination, Consideration Transferred	'	$9,974

Business_Combinations_Allocati

Business Combinations (Allocation of Purchase Price to Assets Acquired and Liabilities Assumed) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012		Jul. 06, 2012	Jun. 05, 2013	Sep. 30, 2013	Apr. 12, 2012
In Thousands, unless otherwise specified				PLX Technology, Inc., [Member]	Mobius [Member]	STB Business [Member]	STB Business [Member]
Business Acquisition [Line Items]	'	'		'	'	'	'
Accounts receivable	'	'		'	'	'	$8,066
Prepaid inventory	'	'		'	'	'	4,310
Inventories	'	'		'	'	'	7,091
Property and equipment, net	'	'		241	9	'	2,433
Other long term assets	'	'		'	'	'	125
Intangible assets	'	'		9,200	12,239	'	46,200
Goodwill	4,688	4,664	[1]	652	752	3,300	3,285
Prepaid expense and other assets	'	'		'	25	'	4,966
Employee compensation liabilities	'	'		-119	'	'	-2,342
Total purchase price	'	'		$9,974	$13,025	'	$74,134
[1]	(1) The unaudited condensed consolidated balance sheet at December 31, 2012 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

Business_Combinations_Recognit

Business Combinations (Recognition of Intangible Assets) (Detail) (USD $)

0 Months Ended

In Thousands, unless otherwise specified

Jul. 06, 2012

Jul. 06, 2012

Jul. 06, 2012

Jul. 06, 2012

Apr. 12, 2012

Apr. 12, 2012

Apr. 12, 2012

Apr. 12, 2012

Apr. 12, 2012

Apr. 12, 2012

Jun. 05, 2013

Jun. 05, 2013

Jun. 05, 2013

PLX Technology, Inc., [Member]

PLX Technology, Inc., [Member]

PLX Technology, Inc., [Member]

PLX Technology, Inc., [Member]

STB Business [Member]

STB Business [Member]

STB Business [Member]

STB Business [Member]

STB Business [Member]

STB Business [Member]

Mobius [Member]

Mobius [Member]

Mobius [Member]

In-Process Research And Development [Member]

Customer Relationships [Member]

Non-Compete Agreements [Member]

Developed Technology [Member]

In-Process Research And Development [Member]

Customer Relationships [Member]

Non-Compete Agreements [Member]

Customer Backlog [Member]

In-Process Research And Development [Member]

Non-Compete Agreements [Member]

Acquired Finite-Lived Intangible Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Total intangible assets, Amount

$9,200

$6,200

$2,900

$100

$46,200

$32,400

$6,500

$3,900

$1,400

$2,000

$12,239

$12,136

$103

Estimated Useful Life

'

'

'7 years

'2 years

'

'4 years

'

'7 years

'2 years

'1 year

'

'

'2 years

Business_Combinations_Suppleme

Business Combinations (Supplemental Pro Forma Information) (Detail) (STB Business [Member], USD $)	3 Months Ended	9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2012	Sep. 30, 2012
STB Business [Member]	'	'
Business Acquisition [Line Items]	'	'
Net revenues	$89,825	$254,697
Net income (loss)	$527	($2,870)
Net income (loss) per share-basic and diluted (in dollars per share)	$0.01	($0.03)

Business_Combinations_Suppleme1

Business Combinations (Supplemental Pro Forma Combined Results of Operations) (Detail) (STB Business [Member], USD $)	3 Months Ended	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2012	Sep. 30, 2012
STB Business [Member]	'	'
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]	'	'
Net impact of the change in amortization of intangibles	$0	($733)
Transaction related expenses related to acquisition	183	4,484
Reorganization expenses related to Trident's bankruptcy filing	0	1,471
Total adjustments	119	9,176
Adjust taxes to the blended rate after business combination	($64)	$3,954

Derivative_Instruments_Details

Derivative Instruments (Details) (USD $)	3 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013
Derivatives [Line Items]	'	'
Foreign currency forward contracts with maturity	'	'12 months
Gain (loss) on fair value hedging contracts	$0.10	$0
Chinese yuan	'	'
Derivatives [Line Items]	'	'
Outstanding contracts to purchase	14	14
Indian rupees	'	'
Derivatives [Line Items]	'	'
Outstanding contracts to purchase	2.8	2.8
British pounds	'	'
Derivatives [Line Items]	'	'
Outstanding contracts to purchase	$1.20	$1.20

Income_Taxes_Narrative_Detail

Income Taxes (Narrative) (Detail) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Disclosure Income Taxes Narrative [Abstract]	'	'	'	'	'
Income Tax Reconciliation, Change in Deferred Tax Assets Valuation Allowance	'	$26,700,000	'	'	'
Income tax expense	($860,000)	'	$1,185,000	$21,737,000	$4,214,000
Pre-tax income tax rate, percentage	7.00%	'	74.00%	-67.00%	49.00%
Effective Income Tax Rate Reconciliation, Perm Items Reserves Uncertain Tax Positions Percentage	'	'	39.00%	'	14.00%

Net_Loss_Income_Per_Common_Sha2

Net (Loss) Income Per Common Share (Schedule of Computation of Basic and Diluted Net Income Per Share) (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Numerator:	'	'	'	'
Net (loss) income—basic and diluted	($11,935)	$408	($54,252)	$4,474
Denominator:	'	'	'	'
Weighted average number of shares used to compute net (loss) income per share—basic	91,069	88,399	90,225	87,913
Effect of dilutive securities:	'	'	'	'
Weighted average number of shares used to compute net (loss) income per share—diluted	91,069	90,885	90,225	89,918
Net (loss) income per share—basic (in dollars per share)	($0.13)	$0	($0.60)	$0.05
Net (loss) income per share—diluted (in dollars per share)	($0.13)	$0	($0.60)	$0.05
ESPP Shares [Member]	'	'	'	'
Effect of dilutive securities:	'	'	'	'
Effect of dilutive securities	0	97	0	75
Stock Award Common Share Equivalents [Member]	'	'	'	'
Effect of dilutive securities:	'	'	'	'
Effect of dilutive securities	0	2,389	0	1,930

Net_Loss_Income_Per_Common_Sha3

Net (Loss) Income Per Common Share (Narrative) (Detail)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Disclosure Net Income Per Common Share Narrative [Abstract]	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	17.1	5.8	14.8	6.3

Share_Repurchase_Program_Detai

Share Repurchase Program (Detail)	Sep. 30, 2013
In Millions, unless otherwise specified
Share Repurchase Program [Abstract]	'
Stock Repurchase Program, Number of Shares Authorized to be Repurchased	30

Significant_Customer_and_Geogr2

Significant Customer and Geographic Information (Schedule of Total Net Revenues or Accounts Receivable from Customers Exceeding 10% of Total) (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Foxconn Electronics, Inc. [Member]	'	'	'	'	'
Concentration Risk [Line Items]	'	'	'	'	'
Net Revenues	23.00%	'	17.00%	'	'
Accounts Receivable	22.00%	'	22.00%	'	'
Motorola Mobility, Inc. [Member]	'	'	'	'	'
Concentration Risk [Line Items]	'	'	'	'	'
Net Revenues	'	12.00%	'	13.00%	'
Accounts Receivable	'	'	'	'	11.00%
Wistron NeWeb Corporation [Member]	'	'	'	'	'
Concentration Risk [Line Items]	'	'	'	'	'
Net Revenues	21.00%	20.00%	17.00%	22.00%	'
Accounts Receivable	23.00%	'	23.00%	'	29.00%

Significant_Customer_and_Geogr3

Significant Customer and Geographic Information (Schedule of Net Revenues and Long-lived Assets Allocated to Geographic Region) (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Geographic Information And International Property, Plant And Equipment [Line Items]	'	'	'	'	'
Net revenues	$56,376,000	$89,825,000	$201,445,000	$231,980,000	'
Long-lived assets, which represent property, plant and equipment, net of accumulated depreciation, located outside	7,500,000	'	7,500,000	'	6,300,000
Asia [Member]	'	'	'	'	'
Geographic Information And International Property, Plant And Equipment [Line Items]	'	'	'	'	'
Net revenues	44,620,000	81,102,000	171,384,000	204,109,000	'
Europe [Member]	'	'	'	'	'
Geographic Information And International Property, Plant And Equipment [Line Items]	'	'	'	'	'
Net revenues	686,000	1,787,000	2,927,000	5,036,000	'
United States [Member]	'	'	'	'	'
Geographic Information And International Property, Plant And Equipment [Line Items]	'	'	'	'	'
Net revenues	2,246,000	1,378,000	5,644,000	2,388,000	'
North America, other [Member]	'	'	'	'	'
Geographic Information And International Property, Plant And Equipment [Line Items]	'	'	'	'	'
Net revenues	$8,824,000	$5,558,000	$21,490,000	$20,447,000	'