Silicon Laboratories (SLAB) 10-Q 24 Oct 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 28, 2013	Oct. 16, 2013
Document and Entity Information
Entity Registrant Name	SILICON LABORATORIES INC
Entity Central Index Key	1038074
Document Type	10-Q
Document Period End Date	28-Sep-13
Amendment Flag	FALSE
Current Fiscal Year End Date	-16
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		43,121,582
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q3

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Sep. 28, 2013	Dec. 29, 2012
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$116,539	$105,426
Short-term investments	153,857	176,565
Accounts receivable, net of allowances for doubtful accounts of $717 at September 28, 2013 and $670 at December 29, 2012	68,499	78,023
Inventories	44,817	49,579
Deferred income taxes	17,356	16,652
Prepaid expenses and other current assets	51,097	41,437
Total current assets	452,165	467,682
Long-term investments	10,671	11,369
Property and equipment, net	134,398	135,271
Goodwill	227,289	130,265
Other intangible assets, net	136,054	90,750
Other assets, net	39,150	36,629
Total assets	999,727	871,966
Current liabilities:
Accounts payable	24,885	29,622
Current portion of long-term debt	5,000	5,000
Accrued expenses	42,639	40,410
Deferred income on shipments to distributors	29,876	30,259
Income taxes	1,457	1,087
Total current liabilities	103,857	106,378
Long-term debt	91,250	95,000
Other non-current liabilities	70,342	20,615
Total liabilities	265,449	221,993
Commitments and contingencies
Stockholders' equity:
Preferred stock--$0.0001 par value; 10,000 shares authorized; no shares issued and outstanding
Common stock--$0.0001 par value; 250,000 shares authorized; 43,093 and 41,879 shares issued and outstanding at September 28, 2013 and December 29, 2012, respectively	4	4
Additional paid-in capital	55,085	10,122
Retained earnings	679,970	640,793
Accumulated other comprehensive loss	-781	-946
Total stockholders' equity	734,278	649,973
Total liabilities and stockholders' equity	$999,727	$871,966

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 28, 2013	Dec. 29, 2012
In Thousands, except Per Share data, unless otherwise specified
Condensed Consolidated Balance Sheets
Accounts receivable, allowances for doubtful accounts (in dollars)	$717	$670
Preferred stock, par value (in dollars per share)	$0.00	$0.00
Preferred stock, shares authorized	10,000	10,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized	250,000	250,000
Common stock, shares issued	43,093	41,879
Common stock, shares outstanding	43,093	41,879

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Condensed Consolidated Statements of Income
Revenues	$146,933	$149,461	$433,851	$410,833
Cost of revenues	58,772	62,968	169,545	166,442
Gross margin	88,161	86,493	264,306	244,391
Operating expenses:
Research and development	40,662	34,768	115,631	101,943
Selling, general and administrative	37,009	24,495	98,519	82,075
Operating expenses	77,671	59,263	214,150	184,018
Operating income	10,490	27,230	50,156	60,373
Other income (expense):
Interest income	129	243	616	1,103
Interest expense	-813	-234	-2,486	-299
Other income (expense), net	-23	-161	39	807
Income before income taxes	9,783	27,078	48,325	61,984
Provision for income taxes	3,252	17,054	9,148	17,131
Net income	$6,531	$10,024	$39,177	$44,853
Earnings per share:
Basic (in dollars per share)	$0.15	$0.24	$0.92	$1.06
Diluted (in dollars per share)	$0.15	$0.24	$0.90	$1.04
Weighted-average common shares outstanding:
Basic (in shares)	42,684	41,735	42,477	42,279
Diluted (in shares)	43,922	42,520	43,437	43,261

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Condensed Consolidated Statements of Comprehensive Income
Net income	$6,531	$10,024	$39,177	$44,853
Net changes to available-for-sale securities
Unrealized gains (losses) arising during the period	653	621	-554	1,138
Reclassification for gains included in net income			-232
Net changes to cash flow hedges
Unrealized gains (losses) arising during the period	-522	-760	622	-898
Reclassification for losses included in net income	96	1,317	418	2,197
Other comprehensive income, before tax	227	1,178	254	2,437
Provision for income taxes	79	412	89	853
Other comprehensive income	148	766	165	1,584
Comprehensive income	$6,679	$10,790	$39,342	$46,437

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 28, 2013	Sep. 29, 2012
Operating Activities
Net income	$39,177	$44,853
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation of property and equipment	10,050	10,247
Net gain on the purchase of property and equipment		-8,457
Amortization of other intangible assets and other assets	11,051	11,001
Stock-based compensation expense	22,304	23,796
Income tax benefit (detriment) from employee stock-based awards	-621	2,301
Excess income tax benefit from employee stock-based awards	-284	-2,470
Deferred income taxes	6,790	5,024
Changes in operating assets and liabilities:
Accounts receivable	12,599	-18,470
Inventories	6,213	-5,994
Prepaid expenses and other assets	-1,606	13,283
Accounts payable	-3,017	9,113
Accrued expenses	-2,864	-797
Deferred income on shipments to distributors	-3,169	5,267
Income taxes	-1,429	-4,378
Net cash provided by operating activities	95,194	84,319
Investing Activities
Purchases of available-for-sale investments	-164,317	-138,822
Proceeds from sales and maturities of available-for-sale investments	186,936	209,972
Purchases of property and equipment	-8,984	-99,720
Purchases of other assets	-3,499	-6,146
Acquisition of businesses, net of cash acquired	-86,441	-71,852
Net cash used in investing activities	-76,305	-106,568
Financing Activities
Proceeds from issuance of common stock, net of shares withheld for taxes	11,900	3,035
Excess income tax benefit from employee stock-based awards	284	2,470
Repurchases of common stock	-7,776	-51,040
Proceeds from issuance of long-term debt, net		98,325
Payments on debt	-12,184
Net cash provided by (used) in financing activities	-7,776	52,790
Increase in cash and cash equivalents	11,113	30,541
Cash and cash equivalents at beginning of period	105,426	94,964
Cash and cash equivalents at end of period	$116,539	$125,505

Significant_Accounting_Policie

Significant Accounting Policies	9 Months Ended
	Sep. 28, 2013
Significant Accounting Policies
Significant Accounting Policies	1.  Significant Accounting Policies
	Basis of Presentation and Principles of Consolidation
	The Condensed Consolidated Financial Statements included herein are unaudited; however, they contain all normal recurring accruals and adjustments which, in the opinion of management, are necessary to present fairly the condensed consolidated financial position of Silicon Laboratories Inc. and its subsidiaries (collectively, the “Company”) at September 28, 2013 and December 29, 2012, the condensed consolidated results of its operations for the three and nine months ended September 28, 2013 and September 29, 2012, the Condensed Consolidated Statements of Comprehensive Income for the three and nine months ended September 28, 2013 and September 29, 2012, and the Condensed Consolidated Statements of Cash Flows for the nine months ended September 28, 2013 and September 29, 2012. All intercompany balances and transactions have been eliminated in consolidation. The condensed consolidated results of operations for the three and nine months ended September 28, 2013 are not necessarily indicative of the results to be expected for the full year.
	The accompanying unaudited Condensed Consolidated Financial Statements do not include certain footnotes and financial presentations normally required under U.S. generally accepted accounting principles (GAAP). Therefore, these Condensed Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and notes thereto for the year ended December 29, 2012, included in the Company’s Form 10-K filed with the Securities and Exchange Commission (SEC) on February 1, 2013.
	The Company prepares financial statements on a 52-53 week year that ends on the Saturday closest to December 31.  Fiscal 2013 will have 52 weeks and fiscal 2012 had 52 weeks.  In a 52-week year, each fiscal quarter consists of 13 weeks.
	Revenue Recognition
	Revenues are generated almost exclusively by sales of the Company’s integrated circuits (ICs). The Company recognizes revenue when all of the following criteria are met: 1) there is persuasive evidence that an arrangement exists, 2) delivery of goods has occurred, 3) the sales price is fixed or determinable, and 4) collectibility is reasonably assured. Generally, revenue from product sales to direct customers and contract manufacturers is recognized upon shipment.
	A portion of the Company’s sales are made to distributors under agreements allowing certain rights of return and price protection related to the final selling price to the end customers. Accordingly, the Company defers revenue and cost of revenue on such sales until the distributors sell the product to the end customers. The net balance of deferred revenue less deferred cost of revenue associated with inventory shipped to a distributor but not yet sold to an end customer is recorded in the deferred income on shipments to distributors liability on the Consolidated Balance Sheet. Such net deferred income balance reflects the Company’s estimate of the impact of rights of return and price protection.
	Recent Accounting Pronouncements
	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 U.S. 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 an impact on the Company’s financial statements, but did amend the disclosures for accumulated other comprehensive loss.

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 28, 2013
Earnings Per Share
Earnings Per Share	2. Earnings Per Share
	The following table sets forth the computation of basic and diluted earnings per share (in thousands, except per share data):
		Three Months Ended				Nine Months Ended
		September 28,		September 29,		September 28,		September 29,
		2013		2012		2013		2012
	Net income	$	6,531	$	10,024	$	39,177	$	44,853
	Shares used in computing basic earnings per share	42,684		41,735		42,477		42,279
	Effect of dilutive securities:
	Stock options and other stock-based awards	1,238		785		960		982
	Shares used in computing diluted earnings per share	43,922		42,520		43,437		43,261
	Earnings per share:
	Basic	$	0.15	$	0.24	$	0.92	$	1.06
	Diluted	$	0.15	$	0.24	$	0.9	$	1.04
	For the three months ended September 28, 2013 and September 29, 2012 and the nine months ended September 28, 2013 and September 29, 2012, approximately 0.5 million, 0.8 million, 0.4 million and 0.9 million shares, respectively, were not included in the diluted earnings per share calculation since the shares were anti-dilutive.

Cash_Cash_Equivalents_and_Inve

Cash, Cash Equivalents and Investments	9 Months Ended
	Sep. 28, 2013
Cash, Cash Equivalents and Investments
Cash, Cash Equivalents and Investments	3. Cash, Cash Equivalents and Investments
	The Company’s cash equivalents and short-term investments as of September 28, 2013 consisted of municipal bonds, money market funds, variable-rate demand notes, corporate bonds, commercial paper, certificates of deposit and asset backed securities. The Company’s long-term investments consisted of auction-rate securities. In fiscal 2008, auctions for many of the Company’s auction-rate securities failed because sell orders exceeded buy orders. As of September 28, 2013, the Company held $12.4 million par value auction-rate securities, all of which have experienced failed auctions. The underlying assets of the securities consisted of student loans and municipal bonds, of which $10.4 million were guaranteed by the U.S. government and the remaining $2.0 million were privately insured. As of September 28, 2013, $6.0 million had credit ratings of AA, $2.0 million had a credit rating of A and $4.4 million of the auction-rate securities had credit ratings of BBB. These securities have contractual maturity dates ranging from 2033 to 2046 at September 28, 2013. The Company is receiving the underlying cash flows on all of its auction-rate securities. The principal amounts associated with failed auctions are not expected to be accessible until a successful auction occurs, the issuer redeems the securities, a buyer is found outside of the auction process or the underlying securities mature. The Company is unable to predict if these funds will become available before their maturity dates.
	The Company does not expect to need access to the capital represented by any of its auction-rate securities prior to their maturities. The Company does not intend to sell, and believes it is not more likely than not that it will be required to sell, its auction-rate securities before their anticipated recovery in market value or final settlement at the underlying par value. The Company believes that the credit ratings and credit support of the security issuers indicate that they have the ability to settle the securities at par value. As such, the Company has determined that no other-than-temporary impairment losses existed as of September 28, 2013.
	The Company’s cash, cash equivalents and investments consist of the following (in thousands):
		September 28, 2013
		Cost		Gross			Gross		Fair Value
				Unrealized			Unrealized
				Losses			Gains
	Cash and Cash Equivalents:
	Cash on hand	$	39,600	$	—		$	—	$	39,600
	Available-for-sale securities:
	Money market funds	61,025		—			—		61,025
	Commercial paper	9,349		—			—		9,349
	Certificates of deposit	6,565		—			—		6,565
	Total available-for-sale securities	76,939		—			—		76,939
	Total cash and cash equivalents	$	116,539	$	—		$	—	$	116,539
	Short-term Investments:
	Available-for-sale securities:
	Municipal bonds	$	93,405	$	(13	)	$	131	$	93,523
	Variable-rate demand notes	33,225		—			—		33,225
	Corporate bonds	19,851		(7		)	57		19,901
	Commercial paper	6,795		—			—		6,795
	Asset-backed securities	412		—			1		413
	Total short-term investments	$	153,688	$	(20	)	$	189	$	153,857
	Long-term Investments:
	Available-for-sale securities:
	Auction rate securities	$	12,425	$	(1,754	)	$	—	$	10,671
	Total long-term investments	$	12,425	$	(1,754	)	$	—	$	10,671
		December 29, 2012
		Cost		Gross			Gross		Fair Value
				Unrealized			Unrealized
				Losses			Gains
	Cash and Cash Equivalents:
	Cash on hand	$	56,690	$	—		$	—	$	56,690
	Available-for-sale securities:
	U.S. Treasury bills	25,049		—			1		25,050
	Money market funds	22,685		—			1		22,686
	Municipal bonds	1,000		—			—		1,000
	Total available-for-sale securities	48,734		—			2		48,736
	Total cash and cash equivalents	$	105,424	$	—		$	2	$	105,426
	Short-term Investments:
	Available-for-sale securities:
	Corporate bonds	$	59,089	$	(5	)	$	267	$	59,351
	Municipal bonds	45,646		(7		)	50		45,689
	Variable-rate demand notes	41,785		—			—		41,785
	Asset-backed securities	15,058		—			11		15,069
	U.S. government bonds	12,638		—			25		12,663
	International government bonds	1,991		—			17		2,008
	Total short-term investments	$	176,207	$	(12	)	$	370	$	176,565
	Long-term Investments:
	Available-for-sale securities:
	Auction rate securities	$	12,525	$	(1,156	)	$	—	$	11,369
	Total long-term investments	$	12,525	$	(1,156	)	$	—	$	11,369
	The available-for-sale investments that were in a continuous unrealized loss position, aggregated by length of time that individual securities have been in a continuous loss position, were as follows (in thousands):
		Less Than 12 Months					12 Months or Greater					Total
	As of September 28, 2013	Fair		Gross			Fair		Gross			Fair		Gross
		Value		Unrealized			Value		Unrealized			Value		Unrealized
				Losses					Losses					Losses
	Municipal bonds	$	14,453	$	(13	)	$	—	$	—		$	14,453	$	(13	)
	Auction rate securities	—		—			10,671		(1,754		)	10,671		(1,754		)
	Corporate bonds	3,716		(7		)	—		—			3,716		(7		)
		$	18,169	$	(20	)	$	10,671	$	(1,754	)	$	28,840	$	(1,774	)
		Less Than 12 Months					12 Months or Greater					Total
	As of December 29, 2012	Fair		Gross			Fair		Gross			Fair		Gross
Value		Unrealized		Value			Unrealized		Value			Unrealized
		Losses					Losses					Losses
Municipal bonds	$	17,152	$	(7	)	$	—	$	—		$	17,152	$	(7	)
Auction rate securities	—		—			11,369		(1,156		)	11,369		(1,156		)
Corporate bonds	9,543		(5		)	—		—			9,543		(5		)
	$	26,695	$	(12	)	$	11,369	$	(1,156	)	$	38,064	$	(1,168	)
The gross unrealized losses as of September 28, 2013 and December 29, 2012 were due primarily to the illiquidity of the Company’s auction-rate securities and, to a lesser extent, to changes in market interest rates.
The following summarizes the contractual underlying maturities of the Company’s available-for-sale investments at September 28, 2013 (in thousands):
	Cost		Fair
			Value
Due in one year or less	$	125,011	$	125,053
Due after one year through ten years	77,491		77,618
Due after ten years	40,550		38,796
	$	243,052	$	241,467

Derivative_Financial_Instrumen

Derivative Financial Instruments	9 Months Ended
	Sep. 28, 2013
Derivative Financial Instruments
Derivative Financial Instruments	4. Derivative Financial Instruments
	The Company is exposed to interest rate fluctuations in the normal course of its business, including through its Credit Facilities. The interest payments on the facility are calculated using a variable-rate of interest. The Company has entered into an interest rate swap agreement with a notional value of $100 million (equal to the full amount borrowed under the Term Loan Facility) and, effectively, converted the LIBOR portion of the variable-rate interest payments to fixed-rate interest payments through July 2017 (the maturity date of the Term Loan Facility). The Company’s objective is to offset increases and decreases in expenses resulting from changes in interest rates with gains and losses on the derivative contract, thereby reducing volatility of earnings. The Company does not use derivative contracts for speculative purposes.
	The Company’s interest rate swap agreement is designated and qualifies as a cash flow hedge. The effective portion of the gain or loss on the interest rate swap is recorded in accumulated other comprehensive loss as a separate component of stockholders’ equity and is subsequently recognized in earnings when the hedged exposure affects earnings. Cash flows from derivatives are classified according to the nature of the cash receipt or payment in the Consolidated Statement of Cash Flows.
	The Company estimates the fair values of derivatives based on quoted prices and market observable data of similar instruments. If the Term Loan Facility or the interest rate swap agreement is terminated prior to maturity, the fair value of the interest rate swap recorded in accumulated other comprehensive loss may be recognized in the Consolidated Statement of Income based on an assessment of the agreements at the time of termination. The Company did not discontinue any cash flow hedges in any of the periods presented.
	The Company measures the effectiveness of its cash flow hedge by comparing the change in fair value of the hedged variable interest payments with the change in fair value of the interest rate swap. The Company recognizes ineffective portions of the hedge, as well as amounts not included in the assessment of effectiveness, in the Consolidated Statement of Income. As of September 28, 2013, no portion of the gains or losses from the Company’s hedging instrument was excluded from the assessment of effectiveness. There was no hedge ineffectiveness for any of the periods presented.
	The Company’s derivative financial instrument consisted of the following (in thousands):
				Fair Value
		Balance Sheet Location		September 28,			December 29,
				2013			2012
	Interest rate swap	Other assets, net		$	383		$	—
		Other non-current liabilities		—			658
	The before-tax effect of derivative instruments in cash flow hedging relationships was as follows (in thousands):
		Gain (Loss) Recognized in OCI						Location of Loss	Loss Reclassified
		on Derivatives						Reclassified into	from Accumulated
		(Effective Portion)						Income	OCI into Income
		during the:							(Effective Portion)
									during the:
		Three Months Ended							Three Months Ended
		September 28,			September 29,				September 28,			September 29,
		2013			2012				2013			2012
	Interest rate swaps	$	(522	)	$	(760	)	Rent expense	$	—		$	(1,317	)
								Interest expense	(96		)	—
		Nine Months Ended							Nine Months Ended
		September 28,			September 29,				September 28,			September 29,
		2013			2012				2013			2012
	Interest rate swaps	$	622		$	(898	)	Rent expense	$	—		$	(2,197	)
								Interest expense	(418		)	—
	The Company expects to reclassify $0.5 million of its interest rate swap losses included in accumulated other comprehensive loss as of September 28, 2013 into earnings in the next 12 months, which would be offset by lower interest payments.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	9 Months Ended
	Sep. 28, 2013
Fair Value of Financial Instruments
Fair Value of Financial Instruments	5. Fair Value of Financial Instruments
	The fair values of the Company’s financial instruments are recorded using a hierarchal disclosure framework based upon the level of subjectivity of the inputs used in measuring assets and liabilities. The three levels are described below:
	Level 1 - Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date.
	Level 2 - Inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly.
	Level 3 - Inputs are unobservable for the asset or liability and are developed based on the best information available in the circumstances, which might include the Company’s own data.
	The following summarizes the valuation of the Company’s financial instruments (in thousands). The tables do not include either cash on hand or assets and liabilities that are measured at historical cost or any basis other than fair value.
			Fair Value Measurements
			at September 28, 2013 Using
	Description		Quoted Prices in		Significant Other			Significant		Total
			Active Markets for		Observable			Unobservable
			Identical Assets		Inputs			Inputs
			(Level 1)		(Level 2)			(Level 3)
	Assets:
	Cash Equivalents:
	Money market funds		$	61,025	$	—		$	—	$	61,025
	Commercial paper		—		9,349			—		9,349
	Certificates of deposit		—		6,565			—		6,565
	Total cash equivalents		$	61,025	$	15,914		$	—	$	76,939
	Short-term Investments:
	Municipal bonds		$	—	$	93,523		$	—	$	93,523
	Variable-rate demand notes		—		33,225			—		33,225
	Corporate bonds		—		19,901			—		19,901
	Commercial paper		—		6,795			—		6,795
	Asset-backed securities		—		413			—		413
	Total short-term investments		$	—	$	153,857		$	—	$	153,857
	Long-term Investments:
	Auction rate securities		$	—	$	—		$	10,671	$	10,671
	Total long-term investments		$	—	$	—		$	10,671	$	10,671
	Other assets, net:
	Derivative instruments		$	—	$	383		$	—	$	383
	Total		$	—	$	383		$	—	$	383
	Total		$	61,025	$	170,154		$	10,671	$	241,850
	Other non-current liabilities:
	Contingent consideration		$	—	$	—		$	14,303	$	14,303
	Total		$	—	$	—		$	14,303	$	14,303
			Fair Value Measurements
			at December 29, 2012 Using
	Description		Quoted Prices in		Significant Other			Significant		Total
			Active Markets for		Observable			Unobservable
			Identical Assets		Inputs			Inputs
			(Level 1)		(Level 2)			(Level 3)
	Assets:
	Cash Equivalents:
	U.S. Treasury bills		$	25,050	$	—		$	—	$	25,050
	Money market funds		22,686		—			—		22,686
	Municipal bonds		—		1,000			—		1,000
	Total cash equivalents		$	47,736	$	1,000		$	—	$	48,736
	Short-term Investments:
	Corporate bonds		$	—	$	59,351		$	—	$	59,351
	Municipal bonds		—		45,689			—		45,689
	Variable-rate demand notes		—		41,785			—		41,785
	Asset-backed securities		—		15,069			—		15,069
	U.S. government bonds		12,663		—			—		12,663
	International government bonds		—		2,008			—		2,008
	Total short-term investments		$	12,663	$	163,902		$	—	$	176,565
	Long-term Investments:
	Auction rate securities		$	—	$	—		$	11,369	$	11,369
	Total long-term investments		$	—	$	—		$	11,369	$	11,369
	Total		$	60,399	$	164,902		$	11,369	$	236,670
	Liabilities:
	Derivative instruments		$	—	$	658		$	—	$	658
	Contingent consideration		—		—			2,750		2,750
	Total		$	—	$	658		$	2,750	$	3,408
	The Company’s cash equivalents and short-term investments that are classified as Level 1 are valued using quoted prices and other relevant information generated by market transactions involving identical assets. Cash equivalents and short-term investments classified as Level 2 are valued using non-binding market consensus prices that are corroborated with observable market data; quoted market prices for similar instruments in active markets; or pricing models, such as a discounted cash flow model, with all significant inputs derived from or corroborated with observable market data. Investments classified as Level 3 are valued using a discounted cash flow model. The assumptions used in preparing the discounted cash flow model include estimates for interest rates, amount of cash flows, expected holding periods of the securities and a discount to reflect the Company’s inability to liquidate the securities. The Company’s derivative instruments are valued using a discounted cash flow model. The assumptions used in preparing the discounted cash flow model include quoted interest swap rates and market observable data of similar instruments.
The Company’s contingent consideration is valued using a Monte Carlo simulation model or a probability weighted discounted cash flow model. The assumptions used in preparing the Monte Carlo simulation model include estimates for revenue growth rates, revenue volatility, contractual terms and discount rates. The assumptions used in preparing the discounted cash flow model include estimates for outcomes if milestone goals are achieved, the probability of achieving each outcome and discount rates.
The following summarizes quantitative information about Level 3 fair value measurements.
Auction rate securities
Fair Value at			Valuation Technique	Unobservable Input		Weighted
September 28, 2013						Average
(000s)
$	10,671		Discounted cash flow	Estimated yield		1.12%
				Expected holding period		10 years
				Estimated discount rate		3.77%
The Company has followed an established internal control procedure used in valuing auction rate securities. The procedure involves the analysis of valuation techniques and evaluation of unobservable inputs commonly used by market participants to price similar instruments, and which have been demonstrated to provide reasonable estimates of prices obtained in actual market transactions. Outputs from the valuation process are assessed against various market sources when they are available, including marketplace quotes, recent trades of similar illiquid securities, benchmark indices and independent pricing services. The technique and unobservable input parameters may be recalibrated periodically to achieve an appropriate estimation of the fair value of the securities.
Significant changes in any of the unobservable inputs used in the fair value measurement of auction rate securities in isolation could result in a significantly lower or higher fair value measurement. An increase in expected yield would result in a higher fair value measurement, whereas an increase in expected holding period or estimated discount rate would result in a lower fair value measurement. Generally, a change in the assumptions used for expected holding period is accompanied by a directionally similar change in the assumptions used for estimated yield and discount rate.
Contingent consideration
Fair Value at			Valuation Technique	Unobservable Input		Range
September 28, 2013
(000s)
$	14,303		Monte Carlo simulation	Expected revenue growth rate		23.0% – 49.1%
				Expected revenue volatility		20.00%
				Expected term		1.3 – 5.3 years
				Estimated discount rate		0.0% – 1.4%
The Company has followed an established internal control procedure used in valuing contingent consideration. The valuation of contingent consideration for the Energy Micro acquisition is based on a Monte Carlo simulation model. The fair value of this valuation is estimated on a quarterly basis through a collaborative effort by the Company’s sales, marketing and finance departments.
Significant changes in any of the unobservable inputs used in the fair value measurement of contingent consideration in isolation could result in a significantly lower or higher fair value. A change in projected revenue growth rates would be accompanied by a directionally similar change in fair value. A change in discount rate would be accompanied by a directionally opposite change in fair value.
The following summarizes the activity in Level 3 financial instruments for the three and nine months ended September 28, 2013 (in thousands):
Assets
Auction Rate Securities		Three Months		Nine Months
		Ended		Ended
Beginning balance		$	10,197	$	11,369
Settlements		—		(100		)
Gain (loss) included in other comprehensive income		474		(598		)
Balance at September 28, 2013		$	10,671	$	10,671
Liabilities
Contingent Consideration (1)		Three Months		Nine Months
		Ended		Ended
Beginning balance		$	—	$	2,750
Issues		13,964		13,964
Loss (gain) recognized in earnings		339		(2,411		)(2)
Balance at September 28, 2013		$	14,303	$	14,303
Net loss for the year included in earnings attributable to contingent consideration still held at the end of the period:		$	339	$	339
(1)         In connection with the acquisition of Energy Micro and Ember, the Company recorded contingent consideration based upon the expected achievement of certain milestone goals. Changes to the fair value of contingent consideration due to changes in assumptions used in preparing the valuation model are recorded in selling, general and administrative expenses in the Consolidated Statement of Income.
(2)         The Company reduced the estimated fair value of the Ember contingent consideration because the milestone goal was not achieved.
Fair values of other financial instruments
The fair value of the Company’s Term Loan Facility approximates its carrying values due to the variable interest rate feature of this instrument. The Company’s other financial instruments, including cash, accounts receivable and accounts payable, are recorded at amounts that approximate their fair values due to their short maturities.

Balance_Sheet_Details

Balance Sheet Details	9 Months Ended
	Sep. 28, 2013
Balance Sheet Details
Balance Sheet Details	6. Balance Sheet Details
	The following shows the details of selected Condensed Consolidated Balance Sheet items (in thousands):
	Inventories
		September 28,		December 29,
		2013		2012
	Work in progress	$	34,936	$	42,103
	Finished goods	9,881		7,476
		$	44,817	$	49,579

Acquisition

Acquisition	9 Months Ended
	Sep. 28, 2013
Acquisition
Acquisition	7. Acquisition
	Energy Micro
	On July 1, 2013, the Company acquired Energy Micro AS, a late-stage private company. Energy Micro designed and developed energy-efficient 32-bit microcontrollers based on ARM® Cortex-M architecture. Energy Micro’s energy-friendly solutions are designed to enable a broad range of power-sensitive applications for the Internet of Things (IoT), including smart energy, home automation, security and portable electronics markets.
	The Company acquired Energy Micro for approximately $140.6 million, including: 1) Initial consideration of $107.4 million; 2) Deferred consideration in the form of a promissory note with an estimated fair value of $19.2 million at the date of acquisition (the promissory note was exchanged for approximately 0.5 million shares of the Company’s restricted stock after a mandatory two-month creditor notice.); and 3) Contingent consideration (the “Earn-Out”) with an estimated fair value of $14.0 million at the date of acquisition. The Earn-Out is payable up to approximately $33.3 million based on the extent to which the annual revenue growth rate from certain Energy Micro and Silicon Laboratories products (the “Earn-Out Products”) exceeds 25% per year, over a five-year period from fiscal 2014 through 2018 (the “Earn-Out Period”). The Earn-Out is payable on an annual basis and in no event shall exceed $6,666,666 per year, unless revenue from the Earn-Out Products exceeds $400 million in a single fiscal year during the Earn-Out Period (in which case, the entire Earn-Out amount less any amounts previously paid will become payable).  Approximately $20.3 million of the initial consideration was held in escrow by the Company as security for breaches of representations and warranties and certain other expressly enumerated matters. The escrow obligation was recorded in other non-current liabilities in the Consolidated Balance Sheet.
	A portion of the Earn-Out (28.76%) is contingent on the continued employment of certain key employees for the three years following the acquisition date (the “Departure Percentage”). The Departure Percentage was accounted for as a transaction separate from the business combination based on its economic substance and will be recorded as post-combination compensation expense in the Company’s financial statements during the Earn-Out period.
	The Company recorded the purchase of Energy Micro using the acquisition method of accounting and accordingly, recognized the assets acquired and liabilities assumed at their fair values as of the date of the acquisition. The results of Energy Micro’s operations are included in the Company’s consolidated results of operations beginning on the date of the acquisition. Pro forma information related to this acquisition has not been presented because it would not be materially different from amounts reported. The Company recorded approximately $2.4 million of acquisition-related costs in selling, general and administrative expenses during the nine months ended September 28, 2013.
	The Company believes that this strategic acquisition will accelerate its deployment of energy-friendly solutions across the IoT industries, while further scaling the Company’s engineering team. These factors contributed to a purchase price that was in excess of the fair value of the net assets acquired and, as a result, the Company recorded goodwill. The goodwill is not deductible for tax purposes. The purchase price was allocated as follows (in thousands):
		Amount			Weighted-Average
					Amortization Period
					(Years)
	Intangible assets:
	In-process research and development	$	18,600		Not amortized
	Core and developed technology	29,100			7
	Customer relationships	6,400			8
	Trademarks	1,300			8
		55,400
	Cash and cash equivalents	919
	Other current assets	5,516
	Goodwill	97,023
	Other non-current assets	5,917
	Current liabilities	(6,255		)
	Non-current deferred tax liabilities, net	(6,212		)
	Long-term debt	(8,434		)
	Other non-current liabilities	(3,292		)
	Total purchase price	$	140,582
	The allocation of the purchase price is preliminary and subject to change, primarily for the valuation of consideration, income tax matters, acquired customer-related contracts, and certain other assets and accruals. Accordingly, adjustments may be made to the values of the assets acquired and liabilities assumed as additional information is obtained about the facts and circumstances that existed at the valuation date.
	In-process research and development (IPR&D) represents acquired technology that had not achieved technological feasibility as of the acquisition date and had no alternative future use. The IPR&D recorded in connection with the acquisition of Energy Micro consisted of a multi-protocol wireless RF solution. The fair value of this technology was determined using the income approach. The discount rate applicable to the cash flows was 13.0%. The remaining research and development efforts include additional design, integration and testing. The significant risks associated with the successful completion of this project include the Company’s potential inability to finish the product designs, produce working models and gain customer acceptance. The Company does not expect the products derived from this technology to begin to contribute to revenues prior to fiscal 2014.
	Corporate Headquarters Buildings
	The Company leased facilities at 400 W. Cesar Chavez (“400 WCC”) and 200 W. Cesar Chavez (“200 WCC”) in Austin, Texas for its corporate headquarters. During the terms of the leases, the Company had options to purchase the buildings for approximately $44.3 million for 400 WCC and $50.1 million for 200 WCC. In September 2012, the Company exercised such options and purchased the facilities.
	The buildings are located on land which is leased through 2099 from a third party. The rents for these ground leases were prepaid for the term of the leases by the previous lessee. The first floor of each building was leased to the same third party for the term of the ground leases. The base rents for the first floor leases were prepaid to the previous owner of the buildings. Portions of the remaining floors were also leased to other tenants.
	The Company determined that the purchase of the facilities represented a business combination. Under the acquisition method of accounting, the assets acquired and liabilities assumed were recorded at their fair values as of the date of the acquisition. The purchase price was allocated as follows (in thousands):
		Amount
	Buildings	$	90,900
	Leasehold interest in ground leases	23,840
	Acquired unfavorable leases	(11,925		)
	Lease-related charges	(8		)
	Net gain on purchase	(8,457		)
	Total purchase price	$	94,350
	The buildings and leasehold interest in ground leases will be depreciated on a straight-line basis over their estimated useful lives of 40 years and 86 years, respectively. Acquired unfavorable leases represent the difference between contractual minimum rental payments due under previously-existing leases in each building and the market rates of those same leases. This amount was recorded in other non-current liabilities in the Consolidated Balance Sheet and will be amortized to rental income over the estimated terms of the leases.
	The purchase of the facilities resulted in a net gain of approximately $8.5 million, which was recorded in selling, general and administrative expenses in the Consolidated Statement of Income. The gain resulted primarily because the assets acquired and liabilities assumed were recorded at their fair values as of the date of the acquisition, which was substantially higher than the purchase prices of the facilities. The purchase prices were fixed at the beginning of the two leases in March 2006 and March 2008. While market prices for such facilities increased over the terms of the leases, the purchase prices remained the same.

Debt

Debt	9 Months Ended
	Sep. 28, 2013
Debt
Debt	8. Debt
	On July 31, 2012, the Company and certain of its domestic subsidiaries (the “Guarantors”) entered into a $230 million five-year Credit Agreement (the “Agreement”). The Agreement consists of a $100 million Term Loan Facility and a $130 million Revolving Credit Facility (collectively, the “Credit Facilities”).
	The Term Loan Facility provides for quarterly principal amortization (equal to 5% of the principal in each of the first two years and 10% of the principal in each of the next three years) with the remaining balance payable upon the maturity date. The Revolving Credit Facility includes a $25 million letter of credit sublimit and a $10 million swingline loan sublimit. The Company has an option to increase the size of the Revolving Credit Facility by up to an aggregate of $50 million in additional commitments, subject to certain conditions. On September 27, 2012, the Company borrowed $100 million under the Term Loan Facility. To date, the Company has not borrowed under the Revolving Credit Facility.
	The Term Loan Facility and Revolving Credit Facility, other than swingline loans, will bear interest at LIBOR plus an applicable margin or, at the option of the Company, a base rate (defined as the highest of the Bank of America prime rate, the Federal Funds rate plus 0.50% and a daily rate equal to one-month LIBOR plus 1.00%) plus an applicable margin. Swingline loans accrue interest at a per annum rate based on the base rate plus the applicable margin for base rate loans. The applicable margins for the LIBOR rate loans range from 1.50% to 2.50% and for base rate loans range from 0.50% to 1.50%, depending in each case, on the leverage ratio as defined in the Agreement. The Company also pays a commitment fee on the unused amount of the Revolving Credit Facility.
	In connection with the closing of the Credit Agreement, the Company entered into a security and pledge agreement. Under the security and pledge agreement, the Company pledged equity securities of certain of its subsidiaries, subject to exceptions and limitations. The Credit Facilities contain various conditions, covenants and representations with which the Company must be in compliance in order to borrow funds and to avoid an event of default, including financial covenants that the Company must maintain a leverage ratio (funded debt/EBITDA) of no more than 2.5 to 1 and a minimum fixed charge coverage ratio (EBITDA/debt payments, income taxes and capital expenditures) of no less than 1.50 to 1. As of September 28, 2013, the Company was in compliance with all covenants of the Credit Facilities.
	As of September 28, 2013, the remaining contractual maturities of the Term Loan Facility were as follows (in thousands):
	Fiscal Year
	2013	$	1,250
	2014	7,500
	2015	10,000
	2016	10,000
	2017	67,500
	Total	$	96,250
	Interest Rate Swap Agreement
	In connection with the $100 million borrowed under the Term Loan Facility, the Company entered into an interest rate swap agreement as a hedge against the LIBOR portion of such variable interest payments. Under the terms of the swap agreement, the Company effectively converted the LIBOR portion of the interest on the Term Loan Facility to a fixed interest rate of 0.764% through the maturity date. As of September 28, 2013, the combined interest rate on the Term Loan Facility (which includes an applicable margin) was 2.514%. See Note 4, Derivative Financial Instruments, for additional information.

Stockholders_Equity

Stockholders' Equity	9 Months Ended
	Sep. 28, 2013
Stockholders' Equity
Stockholders' Equity	9. Stockholders’ Equity
	Common Stock
	The Company issued 1.4 million shares of common stock during the nine months ended September 28, 2013, including approximately 0.5 million shares issued in connection with the acquisition of Energy Micro.
	Share Repurchase Programs
	In January 2013, the Board of Directors authorized a share repurchase program to repurchase up to $50 million of the Company’s common stock through January 2014. In April 2012, the Board of Directors authorized a share repurchase program to repurchase up to $100 million of the Company’s common stock through January 2013. In October 2011, the Board of Directors adopted a share repurchase program to repurchase up to $50 million of the Company’s common stock through April 2012. These programs allow for repurchases to be made in the open market or in private transactions, including structured or accelerated transactions, subject to applicable legal requirements and market conditions. The Company repurchased 0.2 million shares of its common stock for $7.8 million during the nine months ended September 28, 2013. The Company repurchased 1.5 million shares of its common stock for $53.1 million during the nine months ended September 29, 2012.
	Accumulated Other Comprehensive Loss
	The components of accumulated other comprehensive loss, net of taxes, were as follows (in thousands):
		Unrealized Gain			Net Unrealized Losses			Total
		(Loss) on Cash			on Available-For-Sale
		Flow Hedge			Securities
	Balance at December 29, 2012	$	(428	)	$	(518	)	$	(946	)
	Other comprehensive income (loss) before reclassifications	405			(361		)	44
	Amount reclassified from accumulated other comprehensive loss	272			(151		)	121
	Net change for the period	677			(512		)	165
	Balance at September 28, 2013	$	249		$	(1,030	)	$	(781	)
	Reclassifications From Accumulated Other Comprehensive Loss
		Three Months Ended						Nine Months Ended
	Reclassification (in thousands)	September 28,			September 29,			September 28,			September 29,
		2013			2012			2013			2012
	Losses on cash flow hedges to:
	Rent expense	$	—		$	(1,317	)	$	—		$	(2,197	)
	Interest expense	(96		)	—			(418		)	—
	Gains on available-for-sales securities to:
	Interest income	—			—			232			—
		(96		)	(1,317		)	(186		)	(2,197		)
	Income tax benefit	33			461			65			769
	Total reclassifications	$	(63	)	$	(856	)	$	(121	)	$	(1,428	)

StockBased_Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 28, 2013
Stock-Based Compensation
Stock-Based Compensation	10. Stock-Based Compensation
	In fiscal 2009, the stockholders of the Company approved the 2009 Stock Incentive Plan (the “2009 Plan”) and the 2009 Employee Stock Purchase Plan (the “2009 Purchase Plan”). The 2009 Plan is currently effective, and has a term of 10 years from the shareholders’ approval date. The 2009 Purchase Plan became effective upon the termination of the previous Employee Stock Purchase Plan, on April 30, 2010.
	Stock-based compensation costs are based on the fair values on the date of grant for stock options and on the date of enrollment for the employee stock purchase plans, estimated by using the Black-Scholes option-pricing model. The fair values of stock awards and restricted stock units (RSUs) equal their intrinsic value on the date of grant. The fair values of market-based performance awards generally are estimated using a Monte Carlo simulation based on the date of grant.
	The following table presents details of stock-based compensation costs recognized in the Condensed Consolidated Statements of Income (in thousands):
		Three Months Ended				Nine Months Ended
		September 28,		September 29,		September 28,		September 29,
		2013		2012		2013		2012
	Cost of revenues	$	269	$	261	$	785	$	938
	Research and development	3,729		3,039		10,551		9,595
	Selling, general and administrative	4,622		4,631		10,968		13,263
		8,620		7,931		22,304		23,796
	Income tax benefit	904		988		1,822		4,199
		$	7,716	$	6,943	$	20,482	$	19,597
	The Company recorded $0.5 million and $1.9 million in selling, general and administrative expense during the three and nine months ended September 29, 2012, respectively, in connection with modifications to certain stock awards. The Company accelerated the vesting of certain RSUs and market stock units (MSUs) and extended the exercise period of stock options pursuant to a separation agreement between the Company and its former CEO. Stock compensation for the nine months ended September 29, 2012 also included the reversal of previously recognized stock compensation for the modified awards.
	The Company had approximately $60.1 million of total unrecognized compensation costs related to stock awards at September 28, 2013 that are expected to be recognized over a weighted-average period of 2.3 years. There were no significant stock-based compensation costs capitalized into assets in any of the periods presented.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 28, 2013
Commitments and Contingencies
Commitments and Contingencies	11.  Commitments and Contingencies
	Patent Litigation
	In 2012, MaxLinear, Inc., a Delaware corporation, and the Company engaged one another in three patent infringement lawsuits filed in the United States District Court for the Southern District of California, San Diego Division, and in the United States District Court for the Western District of Texas, Austin Division. The Texas Court determined that the dispute concerning MaxLinear’s patents would proceed in the California Court. On May 16, 2013, MaxLinear filed an additional patent infringement lawsuit against the Company in the United States District Court for the Southern District of California. On October 3, 2013, the Company and MaxLinear executed a Settlement Agreement resolving all of the lawsuits between them. MaxLinear granted the Company a license to its patent portfolio for the accused Company products, and the Company granted MaxLinear a license to its patent portfolio for the accused MaxLinear products. As part of the settlement, MaxLinear will make a one-time payment of $1.25 million to the Company. The Company and MaxLinear also entered into a 3-year covenant not to sue and agreed to dismiss all of the pending cases.
	Other
	The Company is involved in various other legal proceedings that have arisen in the normal course of business. While the ultimate results of these matters cannot be predicted with certainty, the Company does not expect them to have a material adverse effect on its consolidated financial statements.

Related_Party_Transaction

Related Party Transaction	9 Months Ended
	Sep. 28, 2013
Related Party Transaction
Related Party Transaction	12. Related Party Transaction
	On March 26, 2013, the Company entered into an agreement to purchase consulting services in connection with the acquisition of Energy Micro. The fees for such services were $1.5 million during the nine months ended September 28, 2013. Mr. Bock, the Company’s President, is also an independent contractor with the consulting entity. Mr. Bock is not providing consulting services to the Company on behalf of the entity. Mr. Bock and the entity have agreed that Mr. Bock will receive no compensation in conjunction with the agreement. Mr. Bock abstained from the negotiations with respect to the agreement between the Company and the entity.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 28, 2013
Income Taxes
Income Taxes	13. Income Taxes
	Provision for income taxes includes both domestic and foreign income taxes at the applicable statutory rates adjusted for non-deductible expenses, research and development tax credits and other permanent differences. Income tax expense was $3.3 million and $17.1 million for the three months ended September 28, 2013 and September 29, 2012, respectively, resulting in effective tax rates of 33.2% and 63.0%, respectively. Income tax expense was $9.1 million and $17.1 million for the nine months ended September 28, 2013 and September 29, 2012, respectively, resulting in effective tax rates of 18.9% and 27.6%, respectively. The effective tax rates for the three and nine months ended September 28, 2013 decreased from the prior periods, primarily due to the prior period tax charge related to the intercompany license of certain technology associated with the acquisition of Ember during 2012 and the recognition of the fiscal 2012 and fiscal 2013 federal research and development tax credits due to the enactment of the American Taxpayer Relief Act of 2012 (the “Act”) on January 2, 2013.  In the three months ended September 28, 2013, the decrease in the effective tax rate was partially offset by a reduction in the foreign tax rate benefit.  In the nine months ended September 28, 2013, the decrease in the effective tax rate was also partially offset by the release during the prior period of unrecognized tax benefits that were determined to be effectively settled during 2012.
	At September 28, 2013, the Company had gross unrecognized tax benefits of $4.8 million, $4.7 million of which would affect the effective tax rate if recognized. The Company recognizes interest and penalties related to unrecognized tax benefits in the provision for income taxes.
	The Company believes it is reasonably possible that the gross unrecognized tax benefits will decrease by approximately $1.4 million in the next 12 months due to the lapse of the statute of limitations applicable to a tax deduction claimed on a prior year foreign tax return.
	The tax years 2006 through 2013 remain open to examination by the major taxing jurisdictions to which the Company is subject. The examination of the Company’s 2009 through 2011 federal income tax returns by the U.S. Internal Revenue Service was completed during the third quarter of 2013 with no material impact on the Company’s financial statements.  The Company is not currently under audit in any other major taxing jurisdiction.

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 28, 2013
Significant Accounting Policies
Revenue Recognition	Revenue Recognition
	Revenues are generated almost exclusively by sales of the Company’s integrated circuits (ICs). The Company recognizes revenue when all of the following criteria are met: 1) there is persuasive evidence that an arrangement exists, 2) delivery of goods has occurred, 3) the sales price is fixed or determinable, and 4) collectibility is reasonably assured. Generally, revenue from product sales to direct customers and contract manufacturers is recognized upon shipment.
	A portion of the Company’s sales are made to distributors under agreements allowing certain rights of return and price protection related to the final selling price to the end customers. Accordingly, the Company defers revenue and cost of revenue on such sales until the distributors sell the product to the end customers. The net balance of deferred revenue less deferred cost of revenue associated with inventory shipped to a distributor but not yet sold to an end customer is recorded in the deferred income on shipments to distributors liability on the Consolidated Balance Sheet. Such net deferred income balance reflects the Company’s estimate of the impact of rights of return and price protection.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 28, 2013
Earnings Per Share
Schedule of computation of basic and diluted earnings per share	The following table sets forth the computation of basic and diluted earnings per share (in thousands, except per share data):
		Three Months Ended				Nine Months Ended
		September 28,		September 29,		September 28,		September 29,
		2013		2012		2013		2012
	Net income	$	6,531	$	10,024	$	39,177	$	44,853
	Shares used in computing basic earnings per share	42,684		41,735		42,477		42,279
	Effect of dilutive securities:
	Stock options and other stock-based awards	1,238		785		960		982
	Shares used in computing diluted earnings per share	43,922		42,520		43,437		43,261
	Earnings per share:
	Basic	$	0.15	$	0.24	$	0.92	$	1.06
	Diluted	$	0.15	$	0.24	$	0.9	$	1.04

Cash_Cash_Equivalents_and_Inve1

Cash, Cash Equivalents and Investments (Tables)	9 Months Ended
	Sep. 28, 2013
Cash, Cash Equivalents and Investments
Schedule of cash, cash equivalents, and investments	The Company’s cash, cash equivalents and investments consist of the following (in thousands):
		September 28, 2013
		Cost		Gross			Gross		Fair Value
				Unrealized			Unrealized
				Losses			Gains
	Cash and Cash Equivalents:
	Cash on hand	$	39,600	$	—		$	—	$	39,600
	Available-for-sale securities:
	Money market funds	61,025		—			—		61,025
	Commercial paper	9,349		—			—		9,349
	Certificates of deposit	6,565		—			—		6,565
	Total available-for-sale securities	76,939		—			—		76,939
	Total cash and cash equivalents	$	116,539	$	—		$	—	$	116,539
	Short-term Investments:
	Available-for-sale securities:
	Municipal bonds	$	93,405	$	(13	)	$	131	$	93,523
	Variable-rate demand notes	33,225		—			—		33,225
	Corporate bonds	19,851		(7		)	57		19,901
	Commercial paper	6,795		—			—		6,795
	Asset-backed securities	412		—			1		413
	Total short-term investments	$	153,688	$	(20	)	$	189	$	153,857
	Long-term Investments:
	Available-for-sale securities:
	Auction rate securities	$	12,425	$	(1,754	)	$	—	$	10,671
	Total long-term investments	$	12,425	$	(1,754	)	$	—	$	10,671
		December 29, 2012
		Cost		Gross			Gross		Fair Value
				Unrealized			Unrealized
				Losses			Gains
	Cash and Cash Equivalents:
	Cash on hand	$	56,690	$	—		$	—	$	56,690
	Available-for-sale securities:
	U.S. Treasury bills	25,049		—			1		25,050
	Money market funds	22,685		—			1		22,686
	Municipal bonds	1,000		—			—		1,000
	Total available-for-sale securities	48,734		—			2		48,736
	Total cash and cash equivalents	$	105,424	$	—		$	2	$	105,426
	Short-term Investments:
	Available-for-sale securities:
	Corporate bonds	$	59,089	$	(5	)	$	267	$	59,351
	Municipal bonds	45,646		(7		)	50		45,689
	Variable-rate demand notes	41,785		—			—		41,785
	Asset-backed securities	15,058		—			11		15,069
	U.S. government bonds	12,638		—			25		12,663
	International government bonds	1,991		—			17		2,008
	Total short-term investments	$	176,207	$	(12	)	$	370	$	176,565
	Long-term Investments:
	Available-for-sale securities:
	Auction rate securities	$	12,525	$	(1,156	)	$	—	$	11,369
	Total long-term investments	$	12,525	$	(1,156	)	$	—	$	11,369
Schedule of available-for-sale investments in continuous unrealized loss position by length of time	The available-for-sale investments that were in a continuous unrealized loss position, aggregated by length of time that individual securities have been in a continuous loss position, were as follows (in thousands):
		Less Than 12 Months					12 Months or Greater					Total
	As of September 28, 2013	Fair		Gross			Fair		Gross			Fair		Gross
		Value		Unrealized			Value		Unrealized			Value		Unrealized
				Losses					Losses					Losses
	Municipal bonds	$	14,453	$	(13	)	$	—	$	—		$	14,453	$	(13	)
	Auction rate securities	—		—			10,671		(1,754		)	10,671		(1,754		)
	Corporate bonds	3,716		(7		)	—		—			3,716		(7		)
		$	18,169	$	(20	)	$	10,671	$	(1,754	)	$	28,840	$	(1,774	)
		Less Than 12 Months					12 Months or Greater					Total
	As of December 29, 2012	Fair		Gross			Fair		Gross			Fair		Gross
		Value		Unrealized			Value		Unrealized			Value		Unrealized
				Losses					Losses					Losses
	Municipal bonds	$	17,152	$	(7	)	$	—	$	—		$	17,152	$	(7	)
	Auction rate securities	—		—			11,369		(1,156		)	11,369		(1,156		)
	Corporate bonds	9,543		(5		)	—		—			9,543		(5		)
		$	26,695	$	(12	)	$	11,369	$	(1,156	)	$	38,064	$	(1,168	)
Summarization of contractual underlying maturities of available-for-sale investments	The following summarizes the contractual underlying maturities of the Company’s available-for-sale investments at September 28, 2013 (in thousands):
		Cost		Fair
				Value
	Due in one year or less	$	125,011	$	125,053
	Due after one year through ten years	77,491		77,618
	Due after ten years	40,550		38,796
		$	243,052	$	241,467

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 28, 2013
Derivative Financial Instruments
Schedule of derivative financial instrument	The Company’s derivative financial instrument consisted of the following (in thousands):
				Fair Value
		Balance Sheet Location		September 28,			December 29,
				2013			2012
	Interest rate swap	Other assets, net		$	383		$	—
		Other non-current liabilities		—			658
Schedule of before-tax effect of derivative instruments in cash flow hedging relationships	The before-tax effect of derivative instruments in cash flow hedging relationships was as follows (in thousands):
		Gain (Loss) Recognized in OCI						Location of Loss	Loss Reclassified
		on Derivatives						Reclassified into	from Accumulated
		(Effective Portion)						Income	OCI into Income
		during the:							(Effective Portion)
									during the:
		Three Months Ended							Three Months Ended
		September 28,			September 29,				September 28,			September 29,
		2013			2012				2013			2012
	Interest rate swaps	$	(522	)	$	(760	)	Rent expense	$	—		$	(1,317	)
								Interest expense	(96		)	—
		Nine Months Ended							Nine Months Ended
		September 28,			September 29,				September 28,			September 29,
		2013			2012				2013			2012
	Interest rate swaps	$	622		$	(898	)	Rent expense	$	—		$	(2,197	)
								Interest expense	(418		)	—

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 28, 2013
Fair Value of Financial Instruments
Financial assets and liabilities measured at fair value on a recurring basis	The following summarizes the valuation of the Company’s financial instruments (in thousands). The tables do not include either cash on hand or assets and liabilities that are measured at historical cost or any basis other than fair value.
			Fair Value Measurements
			at September 28, 2013 Using
	Description		Quoted Prices in		Significant Other			Significant		Total
			Active Markets for		Observable			Unobservable
			Identical Assets		Inputs			Inputs
			(Level 1)		(Level 2)			(Level 3)
	Assets:
	Cash Equivalents:
	Money market funds		$	61,025	$	—		$	—	$	61,025
	Commercial paper		—		9,349			—		9,349
	Certificates of deposit		—		6,565			—		6,565
	Total cash equivalents		$	61,025	$	15,914		$	—	$	76,939
	Short-term Investments:
	Municipal bonds		$	—	$	93,523		$	—	$	93,523
	Variable-rate demand notes		—		33,225			—		33,225
	Corporate bonds		—		19,901			—		19,901
	Commercial paper		—		6,795			—		6,795
	Asset-backed securities		—		413			—		413
	Total short-term investments		$	—	$	153,857		$	—	$	153,857
	Long-term Investments:
	Auction rate securities		$	—	$	—		$	10,671	$	10,671
	Total long-term investments		$	—	$	—		$	10,671	$	10,671
	Other assets, net:
	Derivative instruments		$	—	$	383		$	—	$	383
	Total		$	—	$	383		$	—	$	383
	Total		$	61,025	$	170,154		$	10,671	$	241,850
	Other non-current liabilities:
	Contingent consideration		$	—	$	—		$	14,303	$	14,303
	Total		$	—	$	—		$	14,303	$	14,303
			Fair Value Measurements
			at December 29, 2012 Using
	Description		Quoted Prices in		Significant Other			Significant		Total
			Active Markets for		Observable			Unobservable
			Identical Assets		Inputs			Inputs
			(Level 1)		(Level 2)			(Level 3)
	Assets:
	Cash Equivalents:
	U.S. Treasury bills		$	25,050	$	—		$	—	$	25,050
	Money market funds		22,686		—			—		22,686
	Municipal bonds		—		1,000			—		1,000
	Total cash equivalents		$	47,736	$	1,000		$	—	$	48,736
	Short-term Investments:
	Corporate bonds		$	—	$	59,351		$	—	$	59,351
	Municipal bonds		—		45,689			—		45,689
	Variable-rate demand notes		—		41,785			—		41,785
	Asset-backed securities		—		15,069			—		15,069
	U.S. government bonds		12,663		—			—		12,663
	International government bonds		—		2,008			—		2,008
	Total short-term investments		$	12,663	$	163,902		$	—	$	176,565
	Long-term Investments:
	Auction rate securities		$	—	$	—		$	11,369	$	11,369
	Total long-term investments		$	—	$	—		$	11,369	$	11,369
	Total		$	60,399	$	164,902		$	11,369	$	236,670
	Liabilities:
	Derivative instruments		$	—	$	658		$	—	$	658
	Contingent consideration		—		—			2,750		2,750
	Total		$	—	$	658		$	2,750	$	3,408
Summary of quantitative information about level 3 asset fair value measurements	Fair Value at			Valuation Technique	Unobservable Input		Weighted
	September 28, 2013						Average
	(000s)
	$	10,671		Discounted cash flow	Estimated yield		1.12%
					Expected holding period		10 years
					Estimated discount rate		3.77%
Summary of quantitative information about level 3 liability fair value measurements
	Fair Value at			Valuation Technique	Unobservable Input		Range
	September 28, 2013
	(000s)
	$	14,303		Monte Carlo simulation	Expected revenue growth rate		23.0% – 49.1%
					Expected revenue volatility		20.00%
					Expected term		1.3 – 5.3 years
					Estimated discount rate		0.0% – 1.4%
Summary of activity in Level 3 financial instruments	The following summarizes the activity in Level 3 financial instruments for the three and nine months ended September 28, 2013 (in thousands):
	Assets
	Auction Rate Securities		Three Months		Nine Months
			Ended		Ended
	Beginning balance		$	10,197	$	11,369
	Settlements		—		(100		)
	Gain (loss) included in other comprehensive income		474		(598		)
	Balance at September 28, 2013		$	10,671	$	10,671
	Liabilities
	Contingent Consideration (1)		Three Months		Nine Months
			Ended		Ended
	Beginning balance		$	—	$	2,750
	Issues		13,964		13,964
	Loss (gain) recognized in earnings		339		(2,411		)(2)
	Balance at September 28, 2013		$	14,303	$	14,303
	Net loss for the year included in earnings attributable to contingent consideration still held at the end of the period:		$	339	$	339
	(1)         In connection with the acquisition of Energy Micro and Ember, the Company recorded contingent consideration based upon the expected achievement of certain milestone goals. Changes to the fair value of contingent consideration due to changes in assumptions used in preparing the valuation model are recorded in selling, general and administrative expenses in the Consolidated Statement of Income.
	(2)         The Company reduced the estimated fair value of the Ember contingent consideration because the milestone goal was not achieved.

Balance_Sheet_Details_Tables

Balance Sheet Details (Tables)	9 Months Ended
	Sep. 28, 2013
Balance Sheet Details
Inventories	The following shows the details of selected Condensed Consolidated Balance Sheet items (in thousands):
	Inventories
		September 28,		December 29,
		2013		2012
	Work in progress	$	34,936	$	42,103
	Finished goods	9,881		7,476
		$	44,817	$	49,579

Acquisition_Tables

Acquisition (Tables)	9 Months Ended
	Sep. 28, 2013
Energy Micro
Business acquisition
Schedule of purchase price allocation	The purchase price was allocated as follows (in thousands):
		Amount			Weighted-Average
					Amortization Period
					(Years)
	Intangible assets:
	In-process research and development	$	18,600		Not amortized
	Core and developed technology	29,100			7
	Customer relationships	6,400			8
	Trademarks	1,300			8
		55,400
	Cash and cash equivalents	919
	Other current assets	5,516
	Goodwill	97,023
	Other non-current assets	5,917
	Current liabilities	(6,255		)
	Non-current deferred tax liabilities, net	(6,212		)
	Long-term debt	(8,434		)
	Other non-current liabilities	(3,292		)
	Total purchase price	$	140,582
Corporate Headquarters Buildings
Business acquisition
Schedule of purchase price allocation	The purchase price was allocated as follows (in thousands):
		Amount
	Buildings	$	90,900
	Leasehold interest in ground leases	23,840
	Acquired unfavorable leases	(11,925		)
	Lease-related charges	(8		)
	Net gain on purchase	(8,457		)
	Total purchase price	$	94,350

Debt_Tables

Debt (Tables)	9 Months Ended
	Sep. 28, 2013
Debt
Schedule of remaining contractual maturities of the Term Loan Facility	As of September 28, 2013, the remaining contractual maturities of the Term Loan Facility were as follows (in thousands):
	Fiscal Year
	2013	$	1,250
	2014	7,500
	2015	10,000
	2016	10,000
	2017	67,500
	Total	$	96,250

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 28, 2013
Stockholders' Equity
Schedule of components of accumulated other comprehensive loss, net of taxes	The components of accumulated other comprehensive loss, net of taxes, were as follows (in thousands):
		Unrealized Gain			Net Unrealized Losses			Total
		(Loss) on Cash			on Available-For-Sale
		Flow Hedge			Securities
	Balance at December 29, 2012	$	(428	)	$	(518	)	$	(946	)
	Other comprehensive income (loss) before reclassifications	405			(361		)	44
	Amount reclassified from accumulated other comprehensive loss	272			(151		)	121
	Net change for the period	677			(512		)	165
	Balance at September 28, 2013	$	249		$	(1,030	)	$	(781	)
Schedule of Reclassifications From Accumulated Other Comprehensive Loss
		Three Months Ended						Nine Months Ended
	Reclassification (in thousands)	September 28,			September 29,			September 28,			September 29,
		2013			2012			2013			2012
	Losses on cash flow hedges to:
	Rent expense	$	—		$	(1,317	)	$	—		$	(2,197	)
	Interest expense	(96		)	—			(418		)	—
	Gains on available-for-sales securities to:
	Interest income	—			—			232			—
		(96		)	(1,317		)	(186		)	(2,197		)
	Income tax benefit	33			461			65			769
	Total reclassifications	$	(63	)	$	(856	)	$	(121	)	$	(1,428	)

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 28, 2013
Stock-Based Compensation
Schedule of stock-based compensation costs recognized in Condensed Consolidated Statements of Operations	The following table presents details of stock-based compensation costs recognized in the Condensed Consolidated Statements of Income (in thousands):
		Three Months Ended				Nine Months Ended
		September 28,		September 29,		September 28,		September 29,
		2013		2012		2013		2012
	Cost of revenues	$	269	$	261	$	785	$	938
	Research and development	3,729		3,039		10,551		9,595
	Selling, general and administrative	4,622		4,631		10,968		13,263
		8,620		7,931		22,304		23,796
	Income tax benefit	904		988		1,822		4,199
		$	7,716	$	6,943	$	20,482	$	19,597

Significant_Accounting_Policie2

Significant Accounting Policies (Details)	9 Months Ended	12 Months Ended
	Sep. 28, 2013	Dec. 28, 2013	Dec. 29, 2012
Basis of Presentation and Principles of Consolidation
Length of fiscal year		364 days	364 days
Number of days in each fiscal quarter for 52-week fiscal year	91 days
Minimum
Basis of Presentation and Principles of Consolidation
Length of fiscal year	364 days
Maximum
Basis of Presentation and Principles of Consolidation
Length of fiscal year	371 days

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Earnings Per Share
Net income	$6,531	$10,024	$39,177	$44,853
Shares used in computing basic earnings per share	42,684,000	41,735,000	42,477,000	42,279,000
Effect of dilutive securities:
Stock options and other stock-based awards (in shares)	1,238,000	785,000	960,000	982,000
Shares used in computing diluted earnings per share	43,922,000	42,520,000	43,437,000	43,261,000
Earnings per share:
Basic (in dollars per share)	$0.15	$0.24	$0.92	$1.06
Diluted (in dollars per share)	$0.15	$0.24	$0.90	$1.04
Shares excluded from computation of diluted earning per share	500,000	800,000	400,000	900,000

Cash_Cash_Equivalents_and_Inve2

Cash, Cash Equivalents and Investments (Details) (USD $)	9 Months Ended
	Sep. 28, 2013	Dec. 29, 2012
Cash, Cash Equivalents and Investments
Auction-rate securities guaranteed by the U.S. government	$10,400,000
Auction-rate securities privately insured	2,000,000
Auction-rate securities having credit rating 'AA'	6,000,000
Auction-rate securities having credit rating 'A'	2,000,000
Auction-rate securities having credit rating 'BBB'	4,400,000
Other-than-temporary impairment losses	0
Cash on hand, Cost	39,600,000	56,690,000
Cash on hand, Fair Value	39,600,000	56,690,000
Cash and cash equivalents, Cost	116,539,000	105,424,000
Cash and cash equivalents, Gross Unrealized Gains		2,000
Cash and cash equivalents, Fair Value	116,539,000	105,426,000
Cash Equivalents:
Available-for-sale securities
Available-for-sale securities, Cost	76,939,000	48,734,000
Available-for-sale securities, Gross Unrealized Gains		2,000
Available-for-sale securities, Fair Value	76,939,000	48,736,000
Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost	153,688,000	176,207,000
Available-for-sale securities, Gross Unrealized Losses	-20,000	-12,000
Available-for-sale securities, Gross Unrealized Gains	189,000	370,000
Available-for-sale securities, Fair Value	153,857,000	176,565,000
Long-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost	12,425,000	12,525,000
Available-for-sale securities, Gross Unrealized Losses	-1,754,000	-1,156,000
Available-for-sale securities, Fair Value	10,671,000	11,369,000
U.S. Treasury bills | Cash Equivalents:
Available-for-sale securities
Available-for-sale securities, Cost		25,049,000
Available-for-sale securities, Gross Unrealized Gains		1,000
Available-for-sale securities, Fair Value		25,050,000
Money market funds | Cash Equivalents:
Available-for-sale securities
Available-for-sale securities, Cost	61,025,000	22,685,000
Available-for-sale securities, Gross Unrealized Gains		1,000
Available-for-sale securities, Fair Value	61,025,000	22,686,000
Commercial paper | Cash Equivalents:
Available-for-sale securities
Available-for-sale securities, Cost	9,349,000
Available-for-sale securities, Fair Value	9,349,000
Commercial paper | Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost	6,795,000
Available-for-sale securities, Fair Value	6,795,000
Certificates of deposit | Cash Equivalents:
Available-for-sale securities
Available-for-sale securities, Cost	6,565,000
Available-for-sale securities, Fair Value	6,565,000
Corporate bonds | Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost	19,851,000	59,089,000
Available-for-sale securities, Gross Unrealized Losses	-7,000	-5,000
Available-for-sale securities, Gross Unrealized Gains	57,000	267,000
Available-for-sale securities, Fair Value	19,901,000	59,351,000
Municipal bonds | Cash Equivalents:
Available-for-sale securities
Available-for-sale securities, Cost		1,000,000
Available-for-sale securities, Fair Value		1,000,000
Municipal bonds | Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost	93,405,000	45,646,000
Available-for-sale securities, Gross Unrealized Losses	-13,000	-7,000
Available-for-sale securities, Gross Unrealized Gains	131,000	50,000
Available-for-sale securities, Fair Value	93,523,000	45,689,000
Variable-rate demand notes | Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost	33,225,000	41,785,000
Available-for-sale securities, Fair Value	33,225,000	41,785,000
Asset-backed securities | Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost	412,000	15,058,000
Available-for-sale securities, Gross Unrealized Gains	1,000	11,000
Available-for-sale securities, Fair Value	413,000	15,069,000
U.S. government bonds | Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost		12,638,000
Available-for-sale securities, Gross Unrealized Gains		25,000
Available-for-sale securities, Fair Value		12,663,000
International government bonds | Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost		1,991,000
Available-for-sale securities, Gross Unrealized Gains		17,000
Available-for-sale securities, Fair Value		2,008,000
Auction rate securities | Long-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost	12,425,000	12,525,000
Available-for-sale securities, Gross Unrealized Losses	-1,754,000	-1,156,000
Available-for-sale securities, Fair Value	$10,671,000	$11,369,000

Cash_Cash_Equivalents_and_Inve3

Cash, Cash Equivalents and Investments (Details 2) (USD $)	Sep. 28, 2013	Dec. 29, 2012
In Thousands, unless otherwise specified
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for less than twelve months	$18,169	$26,695
Fair value of available-for-sale securities, continuous loss position for twelve months or longer	10,671	11,369
Total fair value of available-for-sale securities, continuous loss position	28,840	38,064
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses	-20	-12
Available-for-sale securities, continuous loss position for 12 months or greater, gross unrealized losses	-1,754	-1,156
Available-for-sale securities, total gross unrealized losses	-1,774	-1,168
Cost
Due in one year or less, Cost	125,011
Due after one year through ten years, Cost	77,491
Due after ten years, Cost	40,550
Total Cost	243,052
Fair Value
Due in one year or less, Fair Value	125,053
Due after one year through ten years, Fair Value	77,618
Due after ten years, Fair Value	38,796
Total Fair Value	241,467
Municipal bonds
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for less than twelve months	14,453	17,152
Total fair value of available-for-sale securities, continuous loss position	14,453	17,152
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses	-13	-7
Available-for-sale securities, total gross unrealized losses	-13	-7
Auction rate securities
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for twelve months or longer	10,671	11,369
Total fair value of available-for-sale securities, continuous loss position	10,671	11,369
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for 12 months or greater, gross unrealized losses	-1,754	-1,156
Available-for-sale securities, total gross unrealized losses	-1,754	-1,156
Corporate bonds
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for less than twelve months	3,716	9,543
Total fair value of available-for-sale securities, continuous loss position	3,716	9,543
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses	-7	-5
Available-for-sale securities, total gross unrealized losses	($7)	($5)

Derivative_Financial_Instrumen2

Derivative Financial Instruments (Details) (Cash flow hedges, Interest rate swaps, USD $)	Sep. 28, 2013
In Millions, unless otherwise specified
Cash flow hedges | Interest rate swaps
Notional amount
Notional value	$100

Derivative_Financial_Instrumen3

Derivative Financial Instruments (Details 2) (USD $)	9 Months Ended	12 Months Ended
	Sep. 28, 2013	Dec. 29, 2012
Derivative Financial Instruments
Description of variable rate	LIBOR
Gains or losses from the hedging instrument which was excluded from the assessment of effectiveness	$0	$0
Other assets, net
Derivative financial instrument
Fair value of interest rate swap	383,000
Other non-current liabilities
Derivative financial instrument
Fair value of interest rate swap		$658,000

Derivative_Financial_Instrumen4

Derivative Financial Instruments (Details 3) (USD $)	3 Months Ended		9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Derivative Instruments, Gain (Loss)
Reclassification of interest rate swap losses included in accumulated other comprehensive loss into earnings in the next 12 months	$500,000		$500,000
Cash flow hedges | Interest rate swaps
Derivative Instruments, Gain (Loss)
Gain (Loss) Recognized in OCI on Derivatives (Effective Portion) during period	-522,000	-760,000	622,000	-898,000
Cash flow hedges | Interest rate swaps | Rent expenses
Derivative Instruments, Gain (Loss)
Loss Reclassified from Accumulated OCI into Income (Effective Portion), included in rent and interest expense during period		-1,317,000		-2,197,000
Cash flow hedges | Interest rate swaps | Interest expense
Derivative Instruments, Gain (Loss)
Loss Reclassified from Accumulated OCI into Income (Effective Portion), included in rent and interest expense during period	($96,000)		($418,000)

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments (Details) (USD $)	Sep. 28, 2013	Dec. 29, 2012
In Thousands, unless otherwise specified
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	$116,539	$105,426
Total short-term investments	153,857	176,565
Total long-term investments	10,671	11,369
Assets and liabilities measured at fair value on recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	61,025	47,736
Total short-term investments		12,663
Total assets at fair value	61,025	60,399
Assets and liabilities measured at fair value on recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	61,025	22,686
Assets and liabilities measured at fair value on recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Treasury bills
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents		25,050
Assets and liabilities measured at fair value on recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. government bonds
Financial assets and liabilities measured at fair value on a recurring basis
Total short-term investments		12,663
Assets and liabilities measured at fair value on recurring basis | Significant Other Observable Inputs (Level 2)
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	15,914	1,000
Total short-term investments	153,857	163,902
Derivative instruments	383
Other assets, net	383
Total assets at fair value	170,154	164,902
Derivative instruments		658
Total liabilities at fair value		658
Assets and liabilities measured at fair value on recurring basis | Significant Other Observable Inputs (Level 2) | Commercial paper
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	9,349
Total short-term investments	6,795
Assets and liabilities measured at fair value on recurring basis | Significant Other Observable Inputs (Level 2) | Certificates of deposit
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	6,565
Assets and liabilities measured at fair value on recurring basis | Significant Other Observable Inputs (Level 2) | Municipal bonds
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents		1,000
Total short-term investments	93,523	45,689
Assets and liabilities measured at fair value on recurring basis | Significant Other Observable Inputs (Level 2) | Variable-rate demand notes
Financial assets and liabilities measured at fair value on a recurring basis
Total short-term investments	33,225	41,785
Assets and liabilities measured at fair value on recurring basis | Significant Other Observable Inputs (Level 2) | Corporate bonds
Financial assets and liabilities measured at fair value on a recurring basis
Total short-term investments	19,901	59,351
Assets and liabilities measured at fair value on recurring basis | Significant Other Observable Inputs (Level 2) | Asset-backed securities
Financial assets and liabilities measured at fair value on a recurring basis
Total short-term investments	413	15,069
Assets and liabilities measured at fair value on recurring basis | Significant Other Observable Inputs (Level 2) | International government bonds
Financial assets and liabilities measured at fair value on a recurring basis
Total short-term investments		2,008
Assets and liabilities measured at fair value on recurring basis | Significant Unobservable Inputs (Level 3)
Financial assets and liabilities measured at fair value on a recurring basis
Total long-term investments	10,671	11,369
Total assets at fair value	10,671	11,369
Contingent consideration	14,303	2,750
Total liabilities at fair value	14,303	2,750
Assets and liabilities measured at fair value on recurring basis | Significant Unobservable Inputs (Level 3) | Auction rate securities
Financial assets and liabilities measured at fair value on a recurring basis
Total long-term investments	10,671	11,369
Assets and liabilities measured at fair value on recurring basis | Fair Value
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	76,939	48,736
Total short-term investments	153,857	176,565
Total long-term investments	10,671	11,369
Derivative instruments	383
Other assets, net	383
Total assets at fair value	241,850	236,670
Derivative instruments		658
Contingent consideration	14,303	2,750
Total liabilities at fair value	14,303	3,408
Assets and liabilities measured at fair value on recurring basis | Fair Value | Money market funds
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	61,025	22,686
Assets and liabilities measured at fair value on recurring basis | Fair Value | U.S. Treasury bills
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents		25,050
Assets and liabilities measured at fair value on recurring basis | Fair Value | Commercial paper
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	9,349
Total short-term investments	6,795
Assets and liabilities measured at fair value on recurring basis | Fair Value | Certificates of deposit
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	6,565
Assets and liabilities measured at fair value on recurring basis | Fair Value | Municipal bonds
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents		1,000
Total short-term investments	93,523	45,689
Assets and liabilities measured at fair value on recurring basis | Fair Value | Variable-rate demand notes
Financial assets and liabilities measured at fair value on a recurring basis
Total short-term investments	33,225	41,785
Assets and liabilities measured at fair value on recurring basis | Fair Value | Corporate bonds
Financial assets and liabilities measured at fair value on a recurring basis
Total short-term investments	19,901	59,351
Assets and liabilities measured at fair value on recurring basis | Fair Value | Asset-backed securities
Financial assets and liabilities measured at fair value on a recurring basis
Total short-term investments	413	15,069
Assets and liabilities measured at fair value on recurring basis | Fair Value | U.S. government bonds
Financial assets and liabilities measured at fair value on a recurring basis
Total short-term investments		12,663
Assets and liabilities measured at fair value on recurring basis | Fair Value | International government bonds
Financial assets and liabilities measured at fair value on a recurring basis
Total short-term investments		2,008
Assets and liabilities measured at fair value on recurring basis | Fair Value | Auction rate securities
Financial assets and liabilities measured at fair value on a recurring basis
Total long-term investments	$10,671	$11,369

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments (Details 2) (Auction rate securities, Weighted Average, Discounted cash flow)	9 Months Ended
	Sep. 28, 2013
Auction rate securities | Weighted Average | Discounted cash flow
Quantitative information for Level 3 Fair Value Measurements Assets
Estimated yield (as a percent)	1.12%
Expected holding period	10 years
Estimated discount rate (as a percent)	3.77%

Fair_Value_of_Financial_Instru4

Fair Value of Financial Instruments (Details 3) (Contingent consideration, Monte Carlo simulation)	9 Months Ended
	Sep. 28, 2013
Quantitative information for Level 3 fair value measurements liabilities
Expected revenue volatility (as a percent)	20.00%
Low end of range
Quantitative information for Level 3 fair value measurements liabilities
Expected revenue growth rate (as a percent)	23.00%
Expected term	1 year 3 months 18 days
Estimated discount rate (as a percent)	0.00%
High end of range
Quantitative information for Level 3 fair value measurements liabilities
Expected revenue growth rate (as a percent)	49.10%
Expected term	5 years 3 months 18 days
Estimated discount rate (as a percent)	1.40%

Fair_Value_of_Financial_Instru5

Fair Value of Financial Instruments (Details 4) (Assets and liabilities measured at fair value on recurring basis, Auction rate securities, USD $)	3 Months Ended	9 Months Ended
In Thousands, unless otherwise specified	Sep. 28, 2013	Sep. 28, 2013
Assets and liabilities measured at fair value on recurring basis | Auction rate securities
Fair value assets reconciliation of changes
Balance at the beginning of the period	$10,197	$11,369
Settlements		-100
Gain (loss) included in other comprehensive income	474	-598
Balance at the end of the period	$10,671	$10,671

Fair_Value_of_Financial_Instru6

Fair Value of Financial Instruments (Details 5) (USD $)	3 Months Ended	9 Months Ended
In Thousands, unless otherwise specified	Sep. 28, 2013	Sep. 28, 2013
Fair value liabilities reconciliation of changes
Net loss for the year included in earnings attributable to contingent consideration still held at the end of the period:	$339	$339
Assets and liabilities measured at fair value on recurring basis | Contingent consideration
Fair value liabilities reconciliation of changes
Balance at the beginning of the period		2,750
Issues	13,964	13,964
Loss (gain) recognized in earnings	339	-2,411
Balance at the end of the period	$14,303	$14,303

Balance_Sheet_Details_Details

Balance Sheet Details (Details) (USD $)	Sep. 28, 2013	Dec. 29, 2012
In Thousands, unless otherwise specified
Inventories
Work in progress	$34,936	$42,103
Finished goods	9,881	7,476
Total inventories	$44,817	$49,579

Acquisition_Details

Acquisition (Details) (USD $)

9 Months Ended

0 Months Ended

0 Months Ended

9 Months Ended

1 Months Ended

Share data in Millions, unless otherwise specified

Sep. 29, 2012

Sep. 28, 2013

Dec. 29, 2012

Jul. 01, 2013

Sep. 28, 2013

Jul. 01, 2013

Jul. 01, 2013

Jul. 01, 2013

Sep. 28, 2013

Jul. 01, 2013

Sep. 30, 2012

Sep. 30, 2012

Sep. 30, 2012

Energy Micro

Energy Micro

Energy Micro

Energy Micro

Energy Micro

Energy Micro

Energy Micro

Corporate Headquarters Buildings

400 WCC

200 WCC

Core and developed technology

Customer relationships

Trademarks

In-process research and development

In-process research and development

item

Acquisition

Purchase price of acquisition

$140,600,000

Initial consideration

107,400,000

Deferred consideration in the form of a promissory note, fair value

19,200,000

Restricted stock exchanged of promissory note in form of deferred consideration on acquisition

0.5

Mandatory period of creditor notice after which the deferred consideration in the form of a promissory note will be exchanged for the entity's restricted stock

2 months

Earn-Out, fair value

14,000,000

Additional consideration on acquisition

33,300,000

Minimum annual revenue growth for additional consideration (as a percent)

25.00%

Earn out period

5 years

Maximum annual Earn-Out payment

6,666,666

Minimum revenue in single fiscal year from Earn-Out products required to make the entire Earn-Out amount payable

400,000,000

Amount of initial consideration held in escrow by the company as security for breaches of representations and warranties and certain other expressly enumerated matters

20,300,000

Percentage of Earn-Out contingent on the continued employment of certain key employees

28.76%

Period of continued employment of key employees for calculating Earn-out portion following acquisition date

3 years

Acquisition-related costs recorded in selling, general and administrative expenses

2,400,000

Purchase price allocation

Intangible assets

55,400,000

29,100,000

6,400,000

1,300,000

18,600,000

Cash and cash equivalents

919,000

Other current assets

5,516,000

Goodwill

227,289,000

130,265,000

97,023,000

Other non-current assets

5,917,000

Current liabilities

-6,255,000

Non-current deferred tax liabilities, net

-6,212,000

Long-term debt

-8,434,000

Other non-current liabilities

-3,292,000

Total purchase price

140,582,000

94,350,000

Weighted-Average Amortization Period

7 years

8 years

8 years

Discount rate applicable to the cash flows (as a percent)

13.00%

Purchase option price for buildings

44,300,000

50,100,000

Buildings

90,900,000

Leasehold interest in ground leases

23,840,000

Acquired unfavorable leases

-11,925,000

Lease-related charges

-8,000

Net gain on purchase

($8,457,000)

($8,457,000)

Useful life of building

40 years

Useful life of leasehold interest in ground leases

86 years

Number of leases for which purchase prices were fixed

2

Debt_Details

Debt (Details) (USD $)

9 Months Ended

1 Months Ended

9 Months Ended

9 Months Ended

Sep. 28, 2013

Sep. 27, 2012

Jul. 31, 2012

Jul. 31, 2012

Sep. 28, 2013

Sep. 28, 2013

Jul. 31, 2012

Sep. 28, 2013

Sep. 28, 2013

Sep. 28, 2013

Sep. 28, 2013

Sep. 28, 2013

Sep. 28, 2013

Sep. 28, 2013

Sep. 28, 2013

Sep. 28, 2013

Term Loan Facility

Term Loan Facility

Term Loan Facility

Agreement

Agreement

Revolving Credit Facility

Revolving Credit Facility

Term loan facility and revolving credit facility, other than swingline loans

Term loan facility and revolving credit facility, other than swingline loans

Term loan facility and revolving credit facility, other than swingline loans

Term loan facility and revolving credit facility, other than swingline loans

Term loan facility and revolving credit facility, other than swingline loans

Term loan facility and revolving credit facility, other than swingline loans

Term loan facility, revolving credit facility, swingline and other loans

Term loan facility, revolving credit facility, swingline and other loans

Term loan facility, revolving credit facility, swingline and other loans

LIBOR

LIBOR

LIBOR

Federal Funds

Base rate

one-month LIBOR

Base rate

Base rate

Base rate

Low end of range

High end of range

Low end of range

High end of range

Debt

Maximum borrowing capacity

$100,000,000

$230,000,000

$130,000,000

Term of debt instrument

5 years

Percentage of principal amortization in each of the first two years

5.00%

Number of years for which the percentage of principal amortization is five percent

2 years

Percentage of principal amortization in each of the next three years

10.00%

Number of years for which the percentage of principal amortization is ten percent

3 years

Sublimit on letters of credit

25,000,000

Sublimit on swingline loan

10,000,000

Additional increase in borrowing capacity of the line of credit available at the entity's option

50,000,000

Amount borrowed under the term loan facility

100,000,000

Debt Instrument Base rate

LIBOR

Federal Funds rate

Bank of America prime rate

one-month LIBOR

base rate

Interest rate added to the base rate (as a percent)

1.50%

2.50%

0.50%

1.00%

0.50%

1.50%

Maximum leverage ratio

2.5

Minimum fixed charge coverage ratio

1.5

Fixed interest rate percentage

0.76%

Combined interest rate percentage

2.51%

Term Loan Facility

2013

1,250,000

2014

7,500,000

2015

10,000,000

2016

10,000,000

2017

67,500,000

Total debt

$96,250,000

Stockholders_Equity_Details

Stockholders' Equity (Details) (USD $)	3 Months Ended		9 Months Ended				1 Months Ended
Share data in Millions, unless otherwise specified	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 28, 2013	Jan. 31, 2013	Apr. 30, 2012	Oct. 31, 2011
					Unrealized Gain (Loss) on Cash Flow Hedge	Net Unrealized Losses on Available-For-Sale Securities	Maximum	Maximum	Maximum
Stockholders' Equity
Number of shares of common stock issued			1.4
Number of shares issued in connection with the acquisition of Energy Micro			0.5
Stockholders' Equity
Value of common stock board of directors authorized to repurchase (in USD)							$50,000,000	$100,000,000	$50,000,000
Components of accumulated other comprehensive loss, net of taxes
Balance at beginning of the period			-946,000		-428,000	-518,000
Other comprehensive income (loss) before reclassifications			44,000		405,000	-361,000
Amounts reclassified from accumulated other comprehensive loss			121,000		272,000	-151,000
Other comprehensive income	148,000	766,000	165,000	1,584,000	677,000	-512,000
Balance at end of the period	-781,000		-781,000		249,000	-1,030,000
Repurchase of common stock (in shares)			0.2	1.5
Repurchase of common stock			$7,800,000	$53,100,000

Stockholders_Equity_Details_2

Stockholders' Equity (Details 2) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Amounts Reclassified from AOCI
Interest expense	($813)	($234)	($2,486)	($299)
Interest income	129	243	616	1,103
Income before income taxes	9,783	27,078	48,325	61,984
Income tax benefit	-3,252	-17,054	-9,148	-17,131
Net income	6,531	10,024	39,177	44,853
Reclassifications From Accumulated Other Comprehensive Loss
Amounts Reclassified from AOCI
Income before income taxes	-96	-1,317	-186	-2,197
Income tax benefit	33	461	65	769
Net income	-63	-856	-121	-1,428
Losses on cash flow hedge | Reclassifications From Accumulated Other Comprehensive Loss
Amounts Reclassified from AOCI
Rent expense		-1,317		-2,197
Interest expense	-96		-418
Gains on available-for-sales securities | Reclassifications From Accumulated Other Comprehensive Loss
Amounts Reclassified from AOCI
Interest income			$232

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Stock-based compensation costs
Share based compensation cost before tax	$8,620,000	$7,931,000	$22,304,000	$23,796,000
Income tax benefit	904,000	988,000	1,822,000	4,199,000
Share based compensation cost after tax	7,716,000	6,943,000	20,482,000	19,597,000
Net reduction in selling, general and administrative expense		500,000		1,900,000
Total unrecognized compensation costs related to awards	60,100,000		60,100,000
Weighted-average period of recognition of unrecognized compensation costs			2 years 3 months 18 days
2009 Stock Incentive Plan
Stock-based compensation costs
Term of plan			10 years
Cost of revenues
Stock-based compensation costs
Share based compensation cost before tax	269,000	261,000	785,000	938,000
Research and development
Stock-based compensation costs
Share based compensation cost before tax	3,729,000	3,039,000	10,551,000	9,595,000
Selling, general and administrative
Stock-based compensation costs
Share based compensation cost before tax	$4,622,000	$4,631,000	$10,968,000	$13,263,000

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (MaxLinear, USD $)	0 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Oct. 03, 2013	Dec. 31, 2012
		item
MaxLinear
Patent Litigation
Number of patent infringement lawsuits filed		3
One-time payment receivable under the Settlement Agreement	$1.25
Covenant period related to not to sue	3 years

Related_Party_Transaction_Deta

Related Party Transaction (Details) (USD $)	9 Months Ended
	Sep. 28, 2013
Related Party Transaction
Amount paid to related party	$1,500,000
Mr. Bock
Related Party Transaction
Amount paid to related party	$0

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Income Taxes
Income tax expense	$3,252,000	$17,054,000	$9,148,000	$17,131,000
Effective income tax rate (as a percent)	33.20%	63.00%	18.90%	27.60%
Gross unrecognized tax benefits	4,800,000		4,800,000
Gross unrecognized tax benefits which would affect the effective tax rate if recognized	4,700,000		4,700,000
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	$1,400,000		$1,400,000