Silicon Laboratories (SLAB) 10-Q 29 Apr 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Apr. 04, 2015	Apr. 21, 2015
Document and Entity Information
Entity Registrant Name	SILICON LABORATORIES INC
Entity Central Index Key	1038074
Document Type	10-Q
Document Period End Date	4-Apr-15
Amendment Flag	FALSE
Current Fiscal Year End Date	-1
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		42,710,601
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Apr. 04, 2015	Jan. 03, 2015
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$112,710	$141,706
Short-term investments	148,795	193,489
Accounts receivable, net of allowances for doubtful accounts of $785 at April 4, 2015 and $786 at January 3, 2015	66,563	70,367
Inventories	61,078	52,631
Deferred income taxes	17,364	21,173
Prepaid expenses and other current assets	51,301	49,171
Total current assets	457,811	528,537
Long-term investments	7,401	7,419
Property and equipment, net	131,313	132,820
Goodwill	264,687	228,781
Other intangible assets, net	135,049	115,021
Other assets, net	24,965	29,983
Total assets	1,021,226	1,042,561
Current liabilities:
Accounts payable	39,295	38,922
Current portion of long-term debt	10,000	10,000
Accrued expenses	45,391	73,646
Deferred income on shipments to distributors	38,796	38,662
Income taxes	1,340	2,084
Total current liabilities	134,822	163,314
Long-term debt	77,150	77,500
Other non-current liabilities	45,817	43,691
Total liabilities	257,789	284,505
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; 42,689 and 42,225 shares issued and outstanding at April 4, 2015 and January 3, 2015, respectively	4	4
Additional paid-in capital	28,833	29,501
Retained earnings	735,011	728,633
Accumulated other comprehensive loss	-411	-82
Total stockholders' equity	763,437	758,056
Total liabilities and stockholders' equity	$1,021,226	$1,042,561

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Apr. 04, 2015	Jan. 03, 2015
In Thousands, except Per Share data, unless otherwise specified
Condensed Consolidated Balance Sheets
Accounts receivable, allowances for doubtful accounts (in dollars)	$785	$786
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	42,689	42,225
Common stock, shares outstanding	42,689	42,225

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Income (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Apr. 04, 2015	Mar. 29, 2014
Condensed Consolidated Statements of Income
Revenues	$163,705	$145,691
Cost of revenues	67,336	58,586
Gross margin	96,369	87,105
Operating expenses:
Research and development	46,857	42,485
Selling, general and administrative	42,300	34,611
Operating expenses	89,157	77,096
Operating income	7,212	10,009
Other income (expense):
Interest income	192	302
Interest expense	-745	-798
Other income (expense), net	408	67
Income before income taxes	7,067	9,580
Provision for income taxes	689	1,470
Net income	$6,378	$8,110
Earnings per share:
Basic (in dollars per share)	$0.15	$0.19
Diluted (in dollars per share)	$0.15	$0.18
Weighted-average common shares outstanding:
Basic (in shares)	42,412	43,081
Diluted (in shares)	43,149	44,056

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Apr. 04, 2015	Mar. 29, 2014
Condensed Consolidated Statements of Comprehensive Income
Net income	$6,378	$8,110
Net changes to available-for-sale securities:
Unrealized gains (losses) arising during the period	-20	413
Reclassification for losses included in net income	10
Net changes to cash flow hedges:
Unrealized losses arising during the period	-626	-141
Reclassification for losses included in net income	130	143
Other comprehensive income (loss), before tax	-506	415
Provision (benefit) for income taxes	-177	145
Other comprehensive income (loss)	-329	270
Comprehensive income	$6,049	$8,380

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Apr. 04, 2015	Mar. 29, 2014
Operating Activities
Net income	$6,378	$8,110
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation of property and equipment	2,987	3,290
Amortization of other intangible assets and other assets	6,521	4,491
Stock-based compensation expense	10,519	9,277
Income tax benefit (shortfall) from stock-based awards	1,773	45
Excess income tax benefit from stock-based awards	-1,785	-235
Deferred income taxes	6,844	6,784
Changes in operating assets and liabilities:
Accounts receivable	6,564	7,452
Inventories	-6,424	1,083
Prepaid expenses and other assets	8,584	14,266
Accounts payable	447	1,195
Accrued expenses	-5,046	21,367
Deferred income on shipments to distributors	-1,049	1,736
Income taxes	-8,409	-8,324
Other non-current liabilities	-3,816	-23,585
Net cash provided by operating activities	24,088	46,952
Investing Activities
Purchases of available-for-sale investments	-13,037	-43,366
Proceeds from sales and maturities of available-for-sale investments	57,739	28,242
Purchases of property and equipment	-1,991	-1,673
Purchases of other assets	-935	-2,113
Acquisition of business, net of cash acquired	-76,899
Net cash used in investing activities	-35,123	-18,910
Financing Activities
Proceeds from issuance of common stock, net of cash paid for withheld taxes	-2,561	5,496
Excess income tax benefit from stock-based awards	1,785	235
Repurchases of common stock	-10,138
Payment of acquisition-related contingent consideration	-4,464
Payments on debt	-2,583	-1,250
Net cash provided by (used in) financing activities	-17,961	4,481
Increase (decrease) in cash and cash equivalents	-28,996	32,523
Cash and cash equivalents at beginning of period	141,706	95,800
Cash and cash equivalents at end of period	$112,710	$128,323

Significant_Accounting_Policie

Significant Accounting Policies	3 Months Ended
	Apr. 04, 2015
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 April 4, 2015 and January 3, 2015, the condensed consolidated results of its operations for the three months ended April 4, 2015 and March 29, 2014, the Condensed Consolidated Statements of Comprehensive Income for the three months ended April 4, 2015 and March 29, 2014, and the Condensed Consolidated Statements of Cash Flows for the three months ended April 4, 2015 and March 29, 2014. All intercompany balances and transactions have been eliminated in consolidation. The condensed consolidated results of operations for the three months ended April 4, 2015 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 January 3, 2015, included in the Company’s Form 10-K filed with the Securities and Exchange Commission (SEC) on February 6, 2015.
	The Company prepares financial statements on a 52-53 week year that ends on the Saturday closest to December 31. Fiscal 2015 will have 52 weeks. Fiscal 2014 had 53 weeks with the extra week occurring in the fourth quarter of the year. In a 52-week year, each fiscal quarter consists of 13 weeks.
	Reclassifications
	Certain reclassifications have been made to prior year financial statements to conform to current year presentation.
	Revenue Recognition
	Revenues are generated predominately 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.
	A small portion of the Company’s revenues is derived from the sale of patents. The above revenue recognition criteria for patent sales are generally met upon the execution of the patent sale agreement.
	Recent Accounting Pronouncements
	In April 2015, the Financial Accounting Standards Board (FASB) issued FASB Accounting Standards Update (ASU) No. 2015-03, Interest—Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs. The amendments in this update require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. ASU 2015-03 is to be applied retrospectively and represents a change in accounting principle. This ASU is effective for fiscal years beginning after December 15, 2015, including interim periods within those fiscal years. Earlier adoption is permitted for financial statements that have not been previously issued. The Company is currently evaluating the effect that the adoption of this ASU will have on its financial statements.
	In June 2014, the FASB issued FASB ASU No. 2014-12, Compensation — Stock Compensation (Topic 718): Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period. The amendments in this update require that a performance target that affects vesting and that could be achieved after the requisite service period should be treated as a performance condition. A reporting entity should apply existing guidance in Topic 718 as it relates to awards with performance conditions that affect vesting to account for such awards. As such, the performance target should not be reflected in estimating the grant-date fair value of the award. ASU 2014-12 is effective for annual periods and interim periods within those annual periods beginning after December 15, 2015. Earlier adoption is permitted. The Company is currently evaluating the effect that the adoption of this ASU will have on its financial statements.
	In May 2014, the FASB issued FASB ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), which supersedes the revenue recognition requirements in ASC 605, Revenue Recognition. The core principle of ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance provides a five-step process to achieve that core principle. ASU 2014-09 requires disclosures enabling users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Additionally, qualitative and quantitative disclosures are required about contracts with customers, significant judgments and changes in judgments, and assets recognized from the costs to obtain or fulfill a contract. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period, using one of two retrospective application methods. Early application is not permitted. The Company is currently evaluating the effect that the adoption of this ASU will have on its financial statements.

Earnings_Per_Share

Earnings Per Share	3 Months Ended
	Apr. 04, 2015
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
		April 4,		March 29,
		2015		2014
	Net income	$	6,378	$	8,110
	Shares used in computing basic earnings per share	42,412		43,081
	Effect of dilutive securities:
	Stock options and other stock-based awards	737		975
	Shares used in computing diluted earnings per share	43,149		44,056
	Earnings per share:
	Basic	$	0.15	$	0.19
	Diluted	$	0.15	$	0.18
	For the three months ended April 4, 2015 and March 29, 2014, approximately 0.1 million and 0.2 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	3 Months Ended
	Apr. 04, 2015
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 April 4, 2015 consisted of municipal bonds, money market funds, corporate bonds, variable-rate demand notes, certificates of deposit, commercial paper and international government bonds. 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 April 4, 2015, the Company held $8.0 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 $6.0 million were guaranteed by the U.S. government and the remaining $2.0 million were privately insured. As of April 4, 2015, $6.0 million of the auction-rate securities had credit ratings of AA and $2.0 million had a credit rating of A. These securities have contractual maturity dates ranging from 2033 to 2046 at April 4, 2015. 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 April 4, 2015.
	The Company’s cash, cash equivalents and investments consisted of the following (in thousands):
		April 4, 2015
		Cost		Gross			Gross		Fair Value
				Unrealized			Unrealized
				Losses			Gains
	Cash and Cash Equivalents:
	Cash on hand	$	48,302	$	—		$	—	$	48,302
	Available-for-sale securities:
	Money market funds	58,808		—			—		58,808
	Certificates of deposit	5,148		—			—		5,148
	Municipal bonds	452		—			—		452
	Total available-for-sale securities	64,408		—			—		64,408
	Total cash and cash equivalents	$	112,710	$	—		$	—	$	112,710
	Short-term Investments:
	Available-for-sale securities:
	Municipal bonds	$	122,794	$	(19	)	$	142	$	122,917
	Corporate bonds	10,109		(2		)	10		10,117
	Variable-rate demand notes	8,615		—			—		8,615
	Commercial paper	4,898		—			—		4,898
	International government bonds	2,247		—			1		2,248
	Total short-term investments	$	148,663	$	(21	)	$	153	$	148,795
	Long-term Investments:
	Available-for-sale securities:
	Auction rate securities	$	8,000	$	(599	)	$	—	$	7,401
	Total long-term investments	$	8,000	$	(599	)	$	—	$	7,401
		January 3, 2015
		Cost		Gross			Gross		Fair Value
				Unrealized			Unrealized
				Losses			Gains
	Cash and Cash Equivalents:
	Cash on hand	$	52,144	$	—		$	—	$	52,144
	Available-for-sale securities:
	Money market funds	71,415		—			—		71,415
	Certificates of deposit	7,739		—			—		7,739
	Commercial paper	5,348		—			—		5,348
	Municipal bonds	1,756		—			1		1,757
	U.S. government agency	1,202		—			—		1,202
	Corporate bonds	1,101		—			—		1,101
	U.S. government bonds	1,000		—			—		1,000
	Total available-for-sale securities	89,561		—			1		89,562
	Total cash and cash equivalents	$	141,705	$	—		$	1	$	141,706
	Short-term Investments:
	Available-for-sale securities:
	Municipal bonds	$	129,005	$	(25	)	$	172	$	129,152
	Corporate bonds	33,043		(35		)	25		33,033
	Variable-rate demand notes	12,915		—			—		12,915
	Commercial paper	8,995		—			—		8,995
	Asset-backed securities	5,380		(3		)	—		5,377
	International government bonds	2,526		(10		)	—		2,516
	U.S. government bonds	650		—			—		650
	U.S. government agency	601		—			—		601
	Certificates of deposit	250		—			—		250
	Total short-term investments	$	193,365	$	(73	)	$	197	$	193,489
	Long-term Investments:
	Available-for-sale securities:
	Auction rate securities	$	8,000	$	(581	)	$	—	$	7,419
	Total long-term investments	$	8,000	$	(581	)	$	—	$	7,419
	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 April 4, 2015	Fair		Gross			Fair		Gross			Fair		Gross
Value		Unrealized		Value			Unrealized		Value			Unrealized
		Losses					Losses					Losses
Municipal bonds	$	22,285	$	(19	)	$	—	$	—		$	22,285	$	(19	)
Auction rate securities	—		—			7,401		(599		)	7,401		(599		)
Corporate bonds	5,348		(2		)	—		—			5,348		(2		)
	$	27,633	$	(21	)	$	7,401	$	(599	)	$	35,034	$	(620	)
Silicon Laboratories Inc.
Notes to Condensed Consolidated Financial Statements (Continued)
(Unaudited)
	Less Than 12 Months					12 Months or Greater					Total
As of January 3, 2015	Fair		Gross			Fair		Gross			Fair		Gross
	Value		Unrealized			Value		Unrealized			Value		Unrealized
			Losses					Losses					Losses
Municipal bonds	$	23,735	$	(25	)	$	—	$	—		$	23,735	$	(25	)
Corporate bonds	20,327		(35		)	—		—			20,327		(35		)
Auction rate securities	—		—			7,419		(581		)	7,419		(581		)
Asset-backed securities	5,080		(3		)	—		—			5,080		(3		)
International government bond	2,516		(10		)	—		—			2,516		(10		)
	$	51,658	$	(73	)	$	7,419	$	(581	)	$	59,077	$	(654	)
The gross unrealized losses as of April 4, 2015 and January 3, 2015 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 April 4, 2015 (in thousands):
	Cost		Fair
			Value
Due in one year or less	$	165,332	$	165,434
Due after one year through ten years	39,624		39,654
Due after ten years	16,115		15,516
	$	221,071	$	220,604

Derivative_Financial_Instrumen

Derivative Financial Instruments

3 Months Ended

Apr. 04, 2015

Derivative Financial Instruments

Derivative Financial Instruments

4. Derivative Financial Instruments

The Company uses derivative financial instruments to manage certain exposures to the variability of interest rates and foreign currency exchange rates. The Company’s objective is to offset increases and decreases in expenses resulting from these exposures with gains and losses on the derivative contracts, thereby reducing volatility of earnings. The Company does not use derivative contracts for speculative or trading purposes. The Company recognizes derivatives, on a gross basis, in the Consolidated Balance Sheet at fair value. Cash flows from derivatives are classified according to the nature of the cash receipt or payment in the Consolidated Statement of Cash Flows.

Interest Rate Swaps

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 an original 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 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 as interest expense in the Consolidated Statement of Income when the hedged exposure affects earnings.

The Company estimates the fair values of interest rate swaps 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 April 4, 2015, no portion of the gains or losses from the Company’s hedging instrument was excluded from the assessment of effectiveness. Hedge ineffectiveness was not material for any of the periods presented.

The Company’s derivative financial instrument in cash flow hedging relationships consisted of the following (in thousands):

Fair Value

Balance Sheet Location

April 4,

January 3,

2015

2015

Interest rate swap

Other assets, net

$

—

$

331

Other non-current liabilities

165

—

The before-tax effect of derivative instruments in cash flow hedging relationships was as follows (in thousands):

Loss Recognized in

Loss Reclassified

OCI on Derivatives

from Accumulated

(Effective Portion)

OCI into Income

during the:

(Effective Portion)

during the:

Three Months Ended

Location of Loss

Three Months Ended

April 4,

March 29,

Reclassified into

April 4,

March 29,

2015

2014

Income

2015

2014

Interest rate swaps

$

(626

)

$

(141

)

Interest expense

$

(130

)

$

(143

)

The Company expects to reclassify $0.4 million of its interest rate swap losses included in accumulated other comprehensive loss as of April 4, 2015 into earnings in the next 12 months, which would be offset by lower interest payments.

Foreign Currency Forward Contracts

The Company uses foreign currency forward contracts to manage exposure to foreign exchange risk. These instruments are used to reduce the earnings impact that exchange rate fluctuations have on non-U.S. dollar balance sheet exposures. The Company recognizes gains and losses on the foreign currency forward contracts in other income (expense), net in the Consolidated Statement of Income in the same period as the remeasurement loss and gain of the related foreign currency denominated asset or liability. The Company does not apply hedge accounting to its foreign currency derivative instruments.

As of April 4, 2015, the Company held one foreign currency forward contract denominated in Norwegian Krone with a notional value of $6.8 million. The fair value of the contract was not material as of April 4, 2015. The contract has a maturity date of July 1, 2015 and it was not designated as a hedging instrument. The Company held no foreign currency forward contracts during the three months ended March 29, 2014.

The before-tax effect of derivative instruments not designated as hedging instruments was as follows (in thousands):

Gain Recognized in Income

Three Months

Location

Ended

April 4, 2015

Foreign currency forward contracts

$

550

Other income (expense), net

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	3 Months Ended
	Apr. 04, 2015
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 April 4, 2015 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		$	58,808		$	—		$	—	$	58,808
	Certificates of deposit		—			5,148			—		5,148
	Municipal bonds		—			452			—		452
	Total cash equivalents		$	58,808		$	5,600		$	—	$	64,408
	Short-term Investments:
	Municipal bonds		$	—		$	122,917		$	—	$	122,917
	Corporate bonds		—			10,117			—		10,117
	Variable-rate demand notes		—			8,615			—		8,615
	Commercial paper		—			4,898			—		4,898
	International government bonds		—			2,248			—		2,248
	Total short-term investments		$	—		$	148,795		$	—	$	148,795
	Long-term Investments:
	Auction rate securities		$	—		$	—		$	7,401	$	7,401
	Total long-term investments		$	—		$	—		$	7,401	$	7,401
	Total		$	58,808		$	154,395		$	7,401	$	220,604
	Liabilities:
	Accrued expenses:
	Contingent consideration		$	—		$	—		$	3,225	$	3,225
	Other non-current liabilities:
	Contingent consideration		$	—		$	—		$	11,579	$	11,579
	Derivative instruments		—			165			—		165
			$	—		$	165		$	11,579	$	11,744
	Total		$	—		$	165		$	14,804	$	14,969
			Fair Value Measurements
			at January 3, 2015 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		$	71,415		$	—		$	—	$	71,415
	Certificates of deposit		—			7,739			—		7,739
	Commercial paper		—			5,348			—		5,348
	Municipal bonds		—			1,757			—		1,757
	U.S. government agency		—			1,202			—		1,202
	Corporate bonds		—			1,101			—		1,101
	U.S. government bonds		1,000			—			—		1,000
	Total cash equivalents		$	72,415		$	17,147		$	—	$	89,562
	Short-term Investments:
	Municipal bonds		$	—		$	129,152		$	—	$	129,152
	Corporate bonds		—			33,033			—		33,033
	Variable-rate demand notes		—			12,915			—		12,915
	Commercial paper		—			8,995			—		8,995
	Asset-backed securities		—			5,377			—		5,377
	International government bonds		—			2,516			—		2,516
	U.S. government bond		650			—			—		650
	U.S. government agency		—			601			—		601
	Certificates of deposit		—			250			—		250
Total short-term investments		$	650		$	192,839		$	—	$	193,489
Long-term Investments:
Auction rate securities		$	—		$	—		$	7,419	$	7,419
Total long-term investments		$	—		$	—		$	7,419	$	7,419
Other assets, net:
Derivative instruments		$	—		$	331		$	—	$	331
Total		$	—		$	331		$	—	$	331
Total		$	73,065		$	210,317		$	7,419	$	290,801
Liabilities:
Accrued expenses:
Contingent consideration		$	—		$	—		$	4,288	$	4,288
Other non-current liabilities:
Contingent consideration		$	—		$	—		$	14,150	$	14,150
Total		$	—		$	—		$	18,438	$	18,438
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 discounted cash flow models. The assumptions used in preparing the valuation models include quoted interest swap rates, foreign exchange rates, forward and spot prices for currencies, 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 Average
April 4, 2015
(000s)
$	7,401		Discounted cash flow		Estimated yield		0.97	%
					Expected holding period		10 years
					Estimated discount rate		2.96	%
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
April 4, 2015
(000s)
$	14,804		Monte Carlo simulation		Expected revenue growth rate		35.6% — 69.1%
					Expected revenue volatility		20.00%
					Expected term		0.8 years — 3.8 years
					Estimated discount rate		0.23% — 1.58%
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.
The following summarizes the activity in Level 3 financial instruments for the three months ended April 4, 2015 (in thousands):
Assets
Auction Rate Securities		Three Months
		Ended
Beginning balance		$	7,419
Loss included in other comprehensive income (loss)		(18		)
Balance at April 4, 2015		$	7,401
Liabilities
Contingent Consideration (1)		Three Months
		Ended
Beginning balance		$	18,438
Settlements		(4,464		)
Loss recognized in earnings (2)		830
Balance at April 4, 2015		$	14,804
Net loss for the period included in earnings attributable to contingent consideration held at the end of the period:		$	(830	)
	-1		In connection with the acquisition of Energy Micro, 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		Changes to the estimated fair value of contingent consideration were primarily due to revisions to the Company’s expectations of earn-out achievement.
Fair values of other financial instruments
The Company’s Term Loan Facility bears interest at LIBOR plus an applicable margin. The Term Loan Facility is recorded at cost, but is measured at fair value for disclosure purposes. Fair value is estimated based on Level 2 inputs, using a discounted cash flow analysis of future principal payments and projected interest based on current market rates. As of April 4, 2015 and January 3, 2015, the fair value of the Company’s debt under the Term Loan Facility was approximately $84.9 million and $87.4 million, respectively.
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	3 Months Ended
	Apr. 04, 2015
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
		April 4,		January 3,
		2015		2015
	Work in progress	$	45,822	$	40,640
	Finished goods	15,256		11,991
		$	61,078	$	52,631

Acquisitions

Acquisitions	3 Months Ended
	Apr. 04, 2015
Acquisitions
Acquisitions
	7. Acquisitions
	Bluegiga
	On January 30, 2015, the Company acquired Bluegiga Technologies Oy, a private company based in Finland. Bluegiga is a provider of Bluetooth® Smart, Bluetooth Classic and Wi-Fi® modules and software stacks for a multitude of applications in the Internet of Things (IoT), industrial automation, consumer electronics, automotive, retail, residential, and health and fitness markets.
	The Company acquired Bluegiga for cash consideration of approximately $58.0 million. Approximately $9.4 million of the initial consideration was held in escrow as security for breaches of representations and warranties and certain other expressly enumerated matters. The Company recorded the purchase of Bluegiga 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 Bluegiga’s operations are included in the Company’s consolidated results of operations beginning on the date of the acquisition.
	The Company believes that this strategic acquisition will accelerate its entry into the wireless module market. This factor 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	$	5,710		Not amortized
	Developed technology	12,190			8
	Customer relationships	6,670			4
	Trademarks	880			3
		25,450
	Cash and cash equivalents	1,132
	Other current assets	6,156
	Goodwill	35,906
	Other non-current assets	208
	Current liabilities	(3,289		)
	Non-current deferred tax liabilities, net	(5,090		)
	Long-term debt	(2,232		)
	Other non-current liabilities	(219		)
	Total purchase price	$	58,022
	The allocation of the purchase price is preliminary and subject to change, primarily for the valuation of certain assets and accruals and the finalization of income tax matters. 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 Bluegiga consisted primarily of Bluetooth Smart Ready and Bluetooth Smart modules and software stacks. The fair value of these technologies was determined using the income approach. The discount rate applicable to the cash flows was 16.1%. The significant risks associated with the projects include the Company’s potential inability to produce working models and the final products gaining customer acceptance.
	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 $1.2 million of acquisition-related costs in selling, general and administrative expenses during the three months ended April 4, 2015.
	Energy Micro
	On July 1, 2013, the Company acquired Energy Micro AS for approximately $140.6 million, including: 1) Initial consideration of $107.4 million; 2) Deferred consideration with an estimated fair value of $19.2 million at the date of acquisition; 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 on an annual basis over a five-year period from fiscal 2014 through 2018 (the “Earn-Out Period”) 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 withheld by the Company as security for breaches of representations and warranties and certain other expressly enumerated matters (the “Holdback”).
	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.
	In the first quarter of 2015, the Company made the following payments in connection with the acquisition: (a) approximately $20.0 million was paid for the release of the Holdback; and (b) approximately $6.3 million was paid for the first annual period of the Earn-out. Approximately $1.8 million of the Earn-out payment represented the Departure Percentage portion and was recorded as compensation expense during fiscal 2014. The remaining approximately $4.5 million of the Earn-out payment represented additional consideration.

Debt

Debt	3 Months Ended
	Apr. 04, 2015
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 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 April 4, 2015, the Company was in compliance with all covenants of the Credit Facilities.
	As of April 4, 2015, the remaining contractual maturities of the Term Loan Facility were as follows (in thousands):
	Fiscal Year
	2015	$	7,500
	2016	10,000
	2017	67,500
	Total	$	85,000
	The Company assumed $2.2 million of debt in connection with its acquisition of Bluegiga. The debt instruments bear interest at rates between 1.0% and 3.0%. The contractual maturities of a portion of the debt are based on certain financial metrics of the acquired company. The Company estimates that the debt will mature between March 2016 and August 2020.
	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 April 4, 2015, 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	3 Months Ended
	Apr. 04, 2015
Stockholders' Equity
Stockholders' Equity
	9. Stockholders’ Equity
	Common Stock
	The Company issued 0.7 million shares of common stock during the three months ended April 4, 2015.
	Share Repurchase Programs
	The Board of Directors authorized the following share repurchase programs (in thousands):
	Program	Program		Program
	Authorization Date	Termination Date		Amount
	October 2014	December 2015		$	100,000
	January 2014	January 2015		$	100,000
	January 2013	January 2014		$	50,000
	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 $10.1 million during the three months ended April 4, 2015. These shares were retired upon repurchase. The Company did not repurchase any shares of its common stock during the three months ended March 29, 2014.
	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 January 3, 2015	$	215		$	(297	)	$	(82	)
	Other comprehensive income (loss) before reclassifications	(407		)	(13		)	(420		)
	Amount reclassified from accumulated other comprehensive loss	85			6			91
	Net change for the period	(322		)	(7		)	(329		)
	Balance at April 4, 2015	$	(107	)	$	(304	)	$	(411	)
	Reclassifications From Accumulated Other Comprehensive Loss
		Three Months Ended
	Reclassification (in thousands)	April 4,			March 29,
		2015			2014
	Losses on cash flow hedges to:
	Interest expense	$	(130	)	$	(143	)
	Losses on available-for-sale securities to:
	Interest income	(10		)	—
		(140		)	(143		)
	Income tax benefit	49			50
	Total reclassifications	$	(91	)	$	(93	)

StockBased_Compensation

Stock-Based Compensation	3 Months Ended
	Apr. 04, 2015
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”). On April 15, 2014, the stockholders of the Company approved amendments to both the 2009 Plan and the 2009 Purchase Plan. The amendments authorized additional shares of common stock for issuance, to comply with changes in applicable law, improve the Company’s corporate governance and to implement other best practices. The amended plans are currently effective.
	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 stock units (MSUs) 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
		April 4,		March 29,
		2015		2014
	Cost of revenues	$	230	$	195
	Research and development	4,795		4,241
	Selling, general and administrative	5,494		4,841
		10,519		9,277
	Income tax benefit	1,304		1,311
		$	9,215	$	7,966
	The Company had approximately $76.7 million of total unrecognized compensation costs related to granted stock awards as of April 4, 2015 that are expected to be recognized over a weighted-average period of approximately 2.4 years. There were no significant stock-based compensation costs capitalized into assets in any of the periods presented.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Apr. 04, 2015
Commitments and Contingencies
Commitments and Contingencies
	11. Commitments and Contingencies
	Patent Litigation
	On January 21, 2014, Cresta Technology Corporation (“Cresta Technology”), a Delaware corporation, filed a lawsuit against the Company, Samsung Electronics Co., Ltd., Samsung Electronics America, Inc., LG Electronics Inc. and LG Electronics U.S.A., Inc. in the United States District Court in the District of Delaware, alleging infringement of United States Patent Nos. 7,075,585, 7,265,792 and 7,251,466. The lawsuit relates to the Company’s family of television tuner products. Cresta Technology seeks unspecified compensatory and enhanced damages, attorney fees and a permanent injunction. On January 28, 2014, Cresta Technology also filed a complaint with the United States International Trade Commission (“ITC”) alleging infringement of the same patents against the Company, Samsung and LG Electronics and seeking to prevent the importation and sale of allegedly infringing products in the United States. The ITC instituted an investigation based on Cresta Technology’s complaint on February 27, 2014.
	An evidentiary hearing in this ITC Investigation concluded on December 5, 2014. The ITC Administrative Law Judge (“ALJ”) issued an Initial Determination on February 27, 2015, finding that all the patent claims asserted against the Company’s products were either invalid or not infringed. The ALJ also found that Cresta Technology failed to establish the ITC’s domestic industry requirement. Accordingly, the ALJ found no violation by the Company. The Final Determination by the ITC is scheduled to issue on June 29, 2015. The Delaware District Court action has been stayed pending completion of the proceedings in the ITC. The Company intends to vigorously defend against these allegations.
	On May 6, 2014, the Company filed a complaint with the ITC alleging infringement of United States Patent Nos. 6,137,372 and 6,233,441 against Cresta Technology, Hauppauge Digital, Inc., Hauppague Computer Works, Inc., PCTV Systems, S.a.r.l., Luxembourg and PCTV Systems S.a.r.l., seeking to prevent the importation and sale of allegedly infringing products in the United States. On July 1, 2014, the Administrative Law Judge accepted a consent order whereby Cresta Technology will not sell for importation, import or sell in the United States television tuners that infringe the Company’s United States Patent Nos. 6,137,372 and 6,233,441. Accordingly, this ITC investigation has been terminated in its entirety.
	On July 16, 2014, the Company filed a lawsuit against Cresta Technology in the United States District Court in the Northern District of California alleging infringement of United States Patent Nos. 6,308,055, 6,304,146, 6,137,372, 6,233,441, 6,965,761 and 7,353,011. The Company is seeking a permanent injunction stopping the sale of all allegedly infringing Cresta Technology products and an award of damages and attorney fees.
	As is customary in the semiconductor industry, the Company provides indemnification protection to its customers for intellectual property claims related to the Company’s products. The Company has not accrued any material liability on its consolidated balance sheet related to such indemnification obligations in connection with the Cresta Technology litigation.
	At this time, the Company cannot predict the outcome of these matters or the resulting financial impact to it, if any.
	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_Transactions

Related Party Transactions	3 Months Ended
	Apr. 04, 2015
Related Party Transactions
Related Party Transactions
	12. Related Party Transactions
	On July 1, 2013, Geir Førre joined the Company as senior vice president. Mr. Førre was chief executive officer of Energy Micro, until it was acquired by the Company. Mr. Førre was the beneficial owner of approximately 30% of the Energy Micro equity and accordingly received approximately $35 million at closing. In the first quarter of 2015, Mr. Førre received approximately $6.1 million of the $20.0 million paid for the holdback related to potential indemnification claims and approximately $1.9 million of the $6.3 million paid for the fiscal 2014 earn-out. Mr. Førre may receive up to approximately $8.1 million of the remaining potential $26.7 million earn-out for fiscal 2015 through 2018.
	On October 17, 2013, the Company appointed Alf-Egil Bogen to its board of directors. Mr. Bogen was chief marketing officer of Energy Micro, until it was acquired by the Company. Mr. Bogen was the beneficial owner of approximately 2% of the Energy Micro equity and accordingly received approximately $0.9 million at closing. In the first quarter of 2015, Mr. Bogen received approximately $0.4 million of the $20.0 million paid for the holdback related to potential indemnification claims and approximately $0.1 million of the $6.3 million paid for the fiscal 2014 earn-out. Mr. Bogen may receive up to approximately $0.5 million of the remaining potential $26.7 million earn-out for fiscal 2015 through 2018. Mr. Bogen had invested approximately $0.8 million in Energy Micro prior to the acquisition.

Income_Taxes

Income Taxes	3 Months Ended
	Apr. 04, 2015
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 $0.7 million and $1.5 million for the three months ended April 4, 2015 and March 29, 2014, resulting in effective tax rates of 9.7% and 15.3%, respectively. The effective tax rate for the three months ended April 4, 2015 decreased from the prior period, primarily due to an increase in the foreign tax rate benefit in the current period resulting from the completion of payments related to an intercompany licensing transaction. This decrease in the effective tax rate was partially offset by the release during the prior period of unrecognized tax benefits related to an uncertain tax position that was closed by statute.
	At April 4, 2015, the Company had gross unrecognized tax benefits of $3.8 million, all 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 $0.6 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 2010 through 2015 remain open to examination by the major taxing jurisdictions to which the Company is subject. The Company is not currently under audit in any major taxing jurisdiction.

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	3 Months Ended
	Apr. 04, 2015
Significant Accounting Policies
Reclassifications
	Reclassifications
	Certain reclassifications have been made to prior year financial statements to conform to current year presentation.
Revenue Recognition
	Revenue Recognition
	Revenues are generated predominately 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.
	A small portion of the Company’s revenues is derived from the sale of patents. The above revenue recognition criteria for patent sales are generally met upon the execution of the patent sale agreement.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	3 Months Ended
	Apr. 04, 2015
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
		April 4,		March 29,
		2015		2014
	Net income	$	6,378	$	8,110
	Shares used in computing basic earnings per share	42,412		43,081
	Effect of dilutive securities:
	Stock options and other stock-based awards	737		975
	Shares used in computing diluted earnings per share	43,149		44,056
	Earnings per share:
	Basic	$	0.15	$	0.19
	Diluted	$	0.15	$	0.18

Cash_Cash_Equivalents_and_Inve1

Cash, Cash Equivalents and Investments (Tables)	3 Months Ended
	Apr. 04, 2015
Cash, Cash Equivalents and Investments
Schedule of cash, cash equivalents, and investments
	The Company’s cash, cash equivalents and investments consisted of the following (in thousands):
		April 4, 2015
		Cost		Gross			Gross		Fair Value
				Unrealized			Unrealized
				Losses			Gains
	Cash and Cash Equivalents:
	Cash on hand	$	48,302	$	—		$	—	$	48,302
	Available-for-sale securities:
	Money market funds	58,808		—			—		58,808
	Certificates of deposit	5,148		—			—		5,148
	Municipal bonds	452		—			—		452
	Total available-for-sale securities	64,408		—			—		64,408
	Total cash and cash equivalents	$	112,710	$	—		$	—	$	112,710
	Short-term Investments:
	Available-for-sale securities:
	Municipal bonds	$	122,794	$	(19	)	$	142	$	122,917
	Corporate bonds	10,109		(2		)	10		10,117
	Variable-rate demand notes	8,615		—			—		8,615
	Commercial paper	4,898		—			—		4,898
	International government bonds	2,247		—			1		2,248
	Total short-term investments	$	148,663	$	(21	)	$	153	$	148,795
	Long-term Investments:
	Available-for-sale securities:
	Auction rate securities	$	8,000	$	(599	)	$	—	$	7,401
	Total long-term investments	$	8,000	$	(599	)	$	—	$	7,401
		January 3, 2015
		Cost		Gross			Gross		Fair Value
				Unrealized			Unrealized
				Losses			Gains
	Cash and Cash Equivalents:
	Cash on hand	$	52,144	$	—		$	—	$	52,144
	Available-for-sale securities:
	Money market funds	71,415		—			—		71,415
	Certificates of deposit	7,739		—			—		7,739
	Commercial paper	5,348		—			—		5,348
	Municipal bonds	1,756		—			1		1,757
	U.S. government agency	1,202		—			—		1,202
	Corporate bonds	1,101		—			—		1,101
	U.S. government bonds	1,000		—			—		1,000
	Total available-for-sale securities	89,561		—			1		89,562
	Total cash and cash equivalents	$	141,705	$	—		$	1	$	141,706
	Short-term Investments:
	Available-for-sale securities:
	Municipal bonds	$	129,005	$	(25	)	$	172	$	129,152
	Corporate bonds	33,043		(35		)	25		33,033
	Variable-rate demand notes	12,915		—			—		12,915
	Commercial paper	8,995		—			—		8,995
	Asset-backed securities	5,380		(3		)	—		5,377
	International government bonds	2,526		(10		)	—		2,516
	U.S. government bonds	650		—			—		650
	U.S. government agency	601		—			—		601
	Certificates of deposit	250		—			—		250
	Total short-term investments	$	193,365	$	(73	)	$	197	$	193,489
	Long-term Investments:
	Available-for-sale securities:
	Auction rate securities	$	8,000	$	(581	)	$	—	$	7,419
	Total long-term investments	$	8,000	$	(581	)	$	—	$	7,419
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 April 4, 2015	Fair		Gross			Fair		Gross			Fair		Gross
		Value		Unrealized			Value		Unrealized			Value		Unrealized
				Losses					Losses					Losses
	Municipal bonds	$	22,285	$	(19	)	$	—	$	—		$	22,285	$	(19	)
	Auction rate securities	—		—			7,401		(599		)	7,401		(599		)
	Corporate bonds	5,348		(2		)	—		—			5,348		(2		)
		$	27,633	$	(21	)	$	7,401	$	(599	)	$	35,034	$	(620	)
		Less Than 12 Months					12 Months or Greater					Total
	As of January 3, 2015	Fair		Gross			Fair		Gross			Fair		Gross
		Value		Unrealized			Value		Unrealized			Value		Unrealized
				Losses					Losses					Losses
	Municipal bonds	$	23,735	$	(25	)	$	—	$	—		$	23,735	$	(25	)
	Corporate bonds	20,327		(35		)	—		—			20,327		(35		)
	Auction rate securities	—		—			7,419		(581		)	7,419		(581		)
	Asset-backed securities	5,080		(3		)	—		—			5,080		(3		)
	International government bond	2,516		(10		)	—		—			2,516		(10		)
		$	51,658	$	(73	)	$	7,419	$	(581	)	$	59,077	$	(654	)
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 April 4, 2015 (in thousands):
		Cost		Fair
				Value
	Due in one year or less	$	165,332	$	165,434
	Due after one year through ten years	39,624		39,654
	Due after ten years	16,115		15,516
		$	221,071	$	220,604

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)

3 Months Ended

Apr. 04, 2015

Derivative Financial Instruments

Schedule of derivative financial instrument

The Company’s derivative financial instrument in cash flow hedging relationships consisted of the following (in thousands):

Fair Value

Balance Sheet Location

April 4,

January 3,

2015

2015

Interest rate swap

Other assets, net

$

—

$

331

Other non-current liabilities

165

—

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):

Loss Recognized in

Loss Reclassified

OCI on Derivatives

from Accumulated

(Effective Portion)

OCI into Income

during the:

(Effective Portion)

during the:

Three Months Ended

Location of Loss

Three Months Ended

April 4,

March 29,

Reclassified into

April 4,

March 29,

2015

2014

Income

2015

2014

Interest rate swaps

$

(626

)

$

(141

)

Interest expense

$

(130

)

$

(143

)

Schedule of before-tax effect of derivative instruments not designated as hedging instruments

The before-tax effect of derivative instruments not designated as hedging instruments was as follows (in thousands):

Gain Recognized in Income

Three Months

Location

Ended

April 4, 2015

Foreign currency forward contracts

$

550

Other income (expense), net

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Apr. 04, 2015
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):
			Fair Value Measurements
			at April 4, 2015 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		$	58,808		$	—		$	—	$	58,808
	Certificates of deposit		—			5,148			—		5,148
	Municipal bonds		—			452			—		452
	Total cash equivalents		$	58,808		$	5,600		$	—	$	64,408
	Short-term Investments:
	Municipal bonds		$	—		$	122,917		$	—	$	122,917
	Corporate bonds		—			10,117			—		10,117
	Variable-rate demand notes		—			8,615			—		8,615
	Commercial paper		—			4,898			—		4,898
	International government bonds		—			2,248			—		2,248
	Total short-term investments		$	—		$	148,795		$	—	$	148,795
	Long-term Investments:
	Auction rate securities		$	—		$	—		$	7,401	$	7,401
	Total long-term investments		$	—		$	—		$	7,401	$	7,401
	Total		$	58,808		$	154,395		$	7,401	$	220,604
	Liabilities:
	Accrued expenses:
	Contingent consideration		$	—		$	—		$	3,225	$	3,225
	Other non-current liabilities:
	Contingent consideration		$	—		$	—		$	11,579	$	11,579
	Derivative instruments		—			165			—		165
			$	—		$	165		$	11,579	$	11,744
	Total		$	—		$	165		$	14,804	$	14,969
			Fair Value Measurements
			at January 3, 2015 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		$	71,415		$	—		$	—	$	71,415
	Certificates of deposit		—			7,739			—		7,739
	Commercial paper		—			5,348			—		5,348
	Municipal bonds		—			1,757			—		1,757
	U.S. government agency		—			1,202			—		1,202
	Corporate bonds		—			1,101			—		1,101
	U.S. government bonds		1,000			—			—		1,000
	Total cash equivalents		$	72,415		$	17,147		$	—	$	89,562
	Short-term Investments:
	Municipal bonds		$	—		$	129,152		$	—	$	129,152
	Corporate bonds		—			33,033			—		33,033
	Variable-rate demand notes		—			12,915			—		12,915
	Commercial paper		—			8,995			—		8,995
	Asset-backed securities		—			5,377			—		5,377
	International government bonds		—			2,516			—		2,516
	U.S. government bond		650			—			—		650
	U.S. government agency		—			601			—		601
	Certificates of deposit		—			250			—		250
	Total short-term investments		$	650		$	192,839		$	—	$	193,489
	Long-term Investments:
	Auction rate securities		$	—		$	—		$	7,419	$	7,419
	Total long-term investments		$	—		$	—		$	7,419	$	7,419
	Other assets, net:
Derivative instruments		$	—		$	331		$	—	$	331
Total		$	—		$	331		$	—	$	331
Total		$	73,065		$	210,317		$	7,419	$	290,801
Liabilities:
Accrued expenses:
Contingent consideration		$	—		$	—		$	4,288	$	4,288
Other non-current liabilities:
Contingent consideration		$	—		$	—		$	14,150	$	14,150
Total		$	—		$	—		$	18,438	$	18,438
Summary of quantitative information about level 3 asset fair value measurements
	Fair Value at			Valuation Technique		Unobservable Input		Weighted Average
	April 4, 2015
	(000s)
	$	7,401		Discounted cash flow		Estimated yield		0.97	%
						Expected holding period		10 years
						Estimated discount rate		2.96	%
Summary of quantitative information about level 3 liability fair value measurements
	Fair Value at			Valuation Technique		Unobservable Input		Range
	April 4, 2015
	(000s)
	$	14,804		Monte Carlo simulation		Expected revenue growth rate		35.6% — 69.1%
						Expected revenue volatility		20.00%
						Expected term		0.8 years — 3.8 years
						Estimated discount rate		0.23% — 1.58%
Summary of activity in Level 3 financial instruments
	The following summarizes the activity in Level 3 financial instruments for the three months ended April 4, 2015 (in thousands):
	Assets
	Auction Rate Securities		Three Months
			Ended
	Beginning balance		$	7,419
	Loss included in other comprehensive income (loss)		(18		)
	Balance at April 4, 2015		$	7,401
	Liabilities
	Contingent Consideration (1)		Three Months
			Ended
	Beginning balance		$	18,438
	Settlements		(4,464		)
	Loss recognized in earnings (2)		830
	Balance at April 4, 2015		$	14,804
	Net loss for the period included in earnings attributable to contingent consideration held at the end of the period:		$	(830	)
		-1		In connection with the acquisition of Energy Micro, 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		Changes to the estimated fair value of contingent consideration were primarily due to revisions to the Company’s expectations of earn-out achievement.

Balance_Sheet_Details_Tables

Balance Sheet Details (Tables)	3 Months Ended
	Apr. 04, 2015
Balance Sheet Details
Inventories
	The following shows the details of selected Condensed Consolidated Balance Sheet items (in thousands):
	Inventories
		April 4,		January 3,
		2015		2015
	Work in progress	$	45,822	$	40,640
	Finished goods	15,256		11,991
		$	61,078	$	52,631

Acquisitions_Tables

Acquisitions (Tables)	3 Months Ended
	Apr. 04, 2015
Acquisitions
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	$	5,710		Not amortized
	Developed technology	12,190			8
	Customer relationships	6,670			4
	Trademarks	880			3
		25,450
	Cash and cash equivalents	1,132
	Other current assets	6,156
	Goodwill	35,906
	Other non-current assets	208
	Current liabilities	(3,289		)
	Non-current deferred tax liabilities, net	(5,090		)
	Long-term debt	(2,232		)
	Other non-current liabilities	(219		)
	Total purchase price	$	58,022

Debt_Tables

Debt (Tables)	3 Months Ended
	Apr. 04, 2015
Debt
Schedule of remaining contractual maturities of the Term Loan Facility
	As of April 4, 2015, the remaining contractual maturities of the Term Loan Facility were as follows (in thousands):
	Fiscal Year
	2015	$	7,500
	2016	10,000
	2017	67,500
	Total	$	85,000

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	3 Months Ended
	Apr. 04, 2015
Stockholders' Equity
Schedule of share repurchase programs
	The Board of Directors authorized the following share repurchase programs (in thousands):
	Program	Program		Program
	Authorization Date	Termination Date		Amount
	October 2014	December 2015		$	100,000
	January 2014	January 2015		$	100,000
	January 2013	January 2014		$	50,000
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 January 3, 2015	$	215		$	(297	)	$	(82	)
	Other comprehensive income (loss) before reclassifications	(407		)	(13		)	(420		)
	Amount reclassified from accumulated other comprehensive loss	85			6			91
	Net change for the period	(322		)	(7		)	(329		)
	Balance at April 4, 2015	$	(107	)	$	(304	)	$	(411	)
Schedule of Reclassifications From Accumulated Other Comprehensive Loss
		Three Months Ended
	Reclassification (in thousands)	April 4,			March 29,
		2015			2014
	Losses on cash flow hedges to:
	Interest expense	$	(130	)	$	(143	)
	Losses on available-for-sale securities to:
	Interest income	(10		)	—
		(140		)	(143		)
	Income tax benefit	49			50
	Total reclassifications	$	(91	)	$	(93	)

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	3 Months Ended
	Apr. 04, 2015
Stock-Based Compensation
Schedule of stock-based compensation costs recognized in the Consolidated Statements of Income
	The following table presents details of stock-based compensation costs recognized in the Condensed Consolidated Statements of Income (in thousands):
		Three Months Ended
		April 4,		March 29,
		2015		2014
	Cost of revenues	$	230	$	195
	Research and development	4,795		4,241
	Selling, general and administrative	5,494		4,841
		10,519		9,277
	Income tax benefit	1,304		1,311
		$	9,215	$	7,966

Significant_Accounting_Policie2

Significant Accounting Policies (Details)	3 Months Ended	12 Months Ended
	Apr. 04, 2015	Jan. 03, 2015
Basis of Presentation and Principles of Consolidation
Length of fiscal year	364 days	371 days
Number of days in each fiscal quarter for 52-week fiscal year	91 days
Low end of range
Basis of Presentation and Principles of Consolidation
Length of fiscal year	364 days
High end of range
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
In Thousands, except Share data, unless otherwise specified	Apr. 04, 2015	Mar. 29, 2014
Earnings Per Share
Net income	$6,378	$8,110
Shares used in computing basic earnings per share	42,412,000	43,081,000
Effect of dilutive securities:
Stock options and other stock-based awards (in shares)	737,000	975,000
Shares used in computing diluted earnings per share	43,149,000	44,056,000
Earnings per share:
Basic (in dollars per share)	$0.15	$0.19
Diluted (in dollars per share)	$0.15	$0.18
Shares excluded from computation of diluted earning per share	100,000	200,000

Cash_Cash_Equivalents_and_Inve2

Cash, Cash Equivalents and Investments (Details) (USD $)	3 Months Ended
	Apr. 04, 2015	Jan. 03, 2015
Cash, Cash Equivalents and Investments
Auction-rate securities guaranteed by the U.S. government	$6,000,000
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
Other-than-temporary impairment losses	0
Cash on hand, Cost	48,302,000	52,144,000
Cash on hand, Fair Value	48,302,000	52,144,000
Cash and cash equivalents, Cost	112,710,000	141,705,000
Cash and cash equivalents, Gross Unrealized Gains		1,000
Cash and cash equivalents, Fair Value	112,710,000	141,706,000
Available-for-sale securities
Available-for-sale securities, Cost	221,071,000
Cash Equivalents:
Available-for-sale securities
Available-for-sale securities, Cost	64,408,000	89,561,000
Available-for-sale securities, Gross Unrealized Gains		1,000
Available-for-sale securities, Fair Value	64,408,000	89,562,000
Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost	148,663,000	193,365,000
Available-for-sale securities, Gross Unrealized Losses	-21,000	-73,000
Available-for-sale securities, Gross Unrealized Gains	153,000	197,000
Available-for-sale securities, Fair Value	148,795,000	193,489,000
Long-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost	8,000,000	8,000,000
Available-for-sale securities, Gross Unrealized Losses	-599,000	-581,000
Available-for-sale securities, Fair Value	7,401,000	7,419,000
Money market funds | Cash Equivalents:
Available-for-sale securities
Available-for-sale securities, Cost	58,808,000	71,415,000
Available-for-sale securities, Fair Value	58,808,000	71,415,000
Certificates of deposit | Cash Equivalents:
Available-for-sale securities
Available-for-sale securities, Cost	5,148,000	7,739,000
Available-for-sale securities, Fair Value	5,148,000	7,739,000
Certificates of deposit | Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost		250,000
Available-for-sale securities, Fair Value		250,000
Commercial paper | Cash Equivalents:
Available-for-sale securities
Available-for-sale securities, Cost		5,348,000
Available-for-sale securities, Fair Value		5,348,000
Commercial paper | Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost	4,898,000	8,995,000
Available-for-sale securities, Fair Value	4,898,000	8,995,000
Municipal bonds | Cash Equivalents:
Available-for-sale securities
Available-for-sale securities, Cost	452,000	1,756,000
Available-for-sale securities, Gross Unrealized Gains		1,000
Available-for-sale securities, Fair Value	452,000	1,757,000
Municipal bonds | Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost	122,794,000	129,005,000
Available-for-sale securities, Gross Unrealized Losses	-19,000	-25,000
Available-for-sale securities, Gross Unrealized Gains	142,000	172,000
Available-for-sale securities, Fair Value	122,917,000	129,152,000
US government agency | Cash Equivalents:
Available-for-sale securities
Available-for-sale securities, Cost		1,202,000
Available-for-sale securities, Fair Value		1,202,000
US government agency | Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost		601,000
Available-for-sale securities, Fair Value		601,000
Corporate bonds | Cash Equivalents:
Available-for-sale securities
Available-for-sale securities, Cost		1,101,000
Available-for-sale securities, Fair Value		1,101,000
Corporate bonds | Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost	10,109,000	33,043,000
Available-for-sale securities, Gross Unrealized Losses	-2,000	-35,000
Available-for-sale securities, Gross Unrealized Gains	10,000	25,000
Available-for-sale securities, Fair Value	10,117,000	33,033,000
U.S. government bonds | Cash Equivalents:
Available-for-sale securities
Available-for-sale securities, Cost		1,000,000
Available-for-sale securities, Fair Value		1,000,000
U.S. government bonds | Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost		650,000
Available-for-sale securities, Fair Value		650,000
Variable-rate demand notes | Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost	8,615,000	12,915,000
Available-for-sale securities, Fair Value	8,615,000	12,915,000
Asset-backed securities | Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost		5,380,000
Available-for-sale securities, Gross Unrealized Losses		-3,000
Available-for-sale securities, Fair Value		5,377,000
International government bonds | Short-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost	2,247,000	2,526,000
Available-for-sale securities, Gross Unrealized Losses		-10,000
Available-for-sale securities, Gross Unrealized Gains	1,000
Available-for-sale securities, Fair Value	2,248,000	2,516,000
Auction rate securities | Long-term Investments:
Available-for-sale securities
Available-for-sale securities, Cost	8,000,000	8,000,000
Available-for-sale securities, Gross Unrealized Losses	-599,000	-581,000
Available-for-sale securities, Fair Value	$7,401,000	$7,419,000

Cash_Cash_Equivalents_and_Inve3

Cash, Cash Equivalents and Investments (Details 2) (USD $)	Apr. 04, 2015	Jan. 03, 2015
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	$27,633	$51,658
Fair value of available-for-sale securities, continuous loss position for twelve months or longer	7,401	7,419
Total fair value of available-for-sale securities, continuous loss position	35,034	59,077
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses	-21	-73
Available-for-sale securities, continuous loss position for 12 months or greater, gross unrealized losses	-599	-581
Available-for-sale securities, total gross unrealized losses	-620	-654
Cost
Due in one year or less, Cost	165,332
Due after one year through ten years, Cost	39,624
Due after ten years, Cost	16,115
Total Cost	221,071
Fair Value
Due in one year or less, Fair Value	165,434
Due after one year through ten years, Fair Value	39,654
Due after ten years, Fair Value	15,516
Total Fair Value	220,604
Municipal bonds
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for less than twelve months	22,285	23,735
Total fair value of available-for-sale securities, continuous loss position	22,285	23,735
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses	-19	-25
Available-for-sale securities, total gross unrealized losses	-19	-25
Corporate bonds
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for less than twelve months	5,348	20,327
Total fair value of available-for-sale securities, continuous loss position	5,348	20,327
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses	-2	-35
Available-for-sale securities, total gross unrealized losses	-2	-35
Auction rate securities
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for twelve months or longer	7,401	7,419
Total fair value of available-for-sale securities, continuous loss position	7,401	7,419
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for 12 months or greater, gross unrealized losses	-599	-581
Available-for-sale securities, total gross unrealized losses	-599	-581
Asset-backed securities
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for less than twelve months		5,080
Total fair value of available-for-sale securities, continuous loss position		5,080
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses		-3
Available-for-sale securities, total gross unrealized losses		-3
International government bonds
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for less than twelve months		2,516
Total fair value of available-for-sale securities, continuous loss position		2,516
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses		-10
Available-for-sale securities, total gross unrealized losses		($10)

Derivative_Financial_Instrumen2

Derivative Financial Instruments (Details) (Cash flow hedges, Interest rate swaps, USD $)	Apr. 04, 2015
In Millions, unless otherwise specified
Cash flow hedges | Interest rate swaps
Notional amount
Original notional value	$100

Derivative_Financial_Instrumen3

Derivative Financial Instruments (Details 2) (USD $)	3 Months Ended
	Apr. 04, 2015	Jan. 03, 2015
Derivative Financial Instruments
Gains or losses from the hedging instrument which was excluded from the assessment of effectiveness	$0
Other assets, net
Derivative financial instrument
Fair value of interest rate swap		331,000
Other non-current liabilities:
Derivative financial instrument
Fair value of interest rate swap	$165,000

Derivative_Financial_Instrumen4

Derivative Financial Instruments (Details 3) (USD $)	3 Months Ended
	Apr. 04, 2015	Mar. 29, 2014
Derivative Instruments, Gain (Loss)
Reclassification of interest rate swap losses included in accumulated other comprehensive loss into earnings in the next 12 months	$400,000
Not Designated as Hedging Instrument | Foreign currency forward contracts
Derivative Instruments, Gain (Loss)
Number of foreign currency forward contract held	1	0
Original notional value	6,800,000
Not Designated as Hedging Instrument | Foreign currency forward contracts | Other income (expense), net
Derivative Instruments, Gain (Loss)
Gain (Loss) Recognized in Income	550,000
Cash flow hedges | Interest rate swaps
Derivative Instruments, Gain (Loss)
Loss Recognized in OCI on Derivatives (Effective Portion) during period	-626,000	-141,000
Original notional value	100,000,000
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	($130,000)	($143,000)

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments (Details) (USD $)	Apr. 04, 2015	Jan. 03, 2015
In Thousands, unless otherwise specified
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	$112,710	$141,706
Total short-term investments	148,795	193,489
Total long-term investments	7,401	7,419
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	58,808	72,415
Total short-term investments		650
Total assets at fair value	58,808	73,065
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	58,808	71,415
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 cash equivalents		1,000
Total short-term investments		650
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	5,600	17,147
Total short-term investments	148,795	192,839
Derivative instruments		331
Other assets, net		331
Total assets at fair value	154,395	210,317
Total liabilities at fair value	165
Assets and liabilities measured at fair value on recurring basis | Significant Other Observable Inputs (Level 2) | Other non-current liabilities:
Financial assets and liabilities measured at fair value on a recurring basis
Derivative instruments	165
Total liabilities at fair value	165
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	5,148	7,739
Total short-term investments		250
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		5,348
Total short-term investments	4,898	8,995
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	452	1,757
Total short-term investments	122,917	129,152
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	8,615	12,915
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		5,377
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	2,248	2,516
Assets and liabilities measured at fair value on recurring basis | Significant Other Observable Inputs (Level 2) | US government agency
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents		1,202
Total short-term investments		601
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 cash equivalents		1,101
Total short-term investments	10,117	33,033
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	7,401	7,419
Total assets at fair value	7,401	7,419
Total liabilities at fair value	14,804	18,438
Assets and liabilities measured at fair value on recurring basis | Significant Unobservable Inputs (Level 3) | Accrued expenses:
Financial assets and liabilities measured at fair value on a recurring basis
Contingent consideration	3,225	4,288
Assets and liabilities measured at fair value on recurring basis | Significant Unobservable Inputs (Level 3) | Other non-current liabilities:
Financial assets and liabilities measured at fair value on a recurring basis
Contingent consideration	11,579	14,150
Total liabilities at fair value	11,579
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	7,401	7,419
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	64,408	89,562
Total short-term investments	148,795	193,489
Total long-term investments	7,401	7,419
Derivative instruments		331
Other assets, net		331
Total assets at fair value	220,604	290,801
Total liabilities at fair value	14,969	18,438
Assets and liabilities measured at fair value on recurring basis | Fair Value | Accrued expenses:
Financial assets and liabilities measured at fair value on a recurring basis
Contingent consideration	3,225	4,288
Assets and liabilities measured at fair value on recurring basis | Fair Value | Other non-current liabilities:
Financial assets and liabilities measured at fair value on a recurring basis
Contingent consideration	11,579	14,150
Derivative instruments	165
Total liabilities at fair value	11,744
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	58,808	71,415
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	5,148	7,739
Total short-term investments		250
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		5,348
Total short-term investments	4,898	8,995
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	452	1,757
Total short-term investments	122,917	129,152
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	8,615	12,915
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		5,377
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	2,248	2,516
Assets and liabilities measured at fair value on recurring basis | Fair Value | US government agency
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents		1,202
Total short-term investments		601
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 cash equivalents		1,101
Total short-term investments	10,117	33,033
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 cash equivalents		1,000
Total short-term investments		650
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	$7,401	$7,419

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments (Details 2) (Auction rate securities, Weighted Average, Discounted cash flow)	3 Months Ended
	Apr. 04, 2015
Auction rate securities | Weighted Average | Discounted cash flow
Quantitative information for Level 3 Fair Value Measurements Assets
Estimated yield (as a percent)	0.97%
Expected holding period	10 years
Estimated discount rate (as a percent)	2.96%

Fair_Value_of_Financial_Instru4

Fair Value of Financial Instruments (Details 3) (Contingent consideration, Monte Carlo simulation)	3 Months Ended
	Apr. 04, 2015
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)	35.60%
Expected term	9 months 18 days
Estimated discount rate (as a percent)	0.23%
High end of range
Quantitative information for Level 3 fair value measurements liabilities
Expected revenue growth rate (as a percent)	69.10%
Expected term	3 years 9 months 18 days
Estimated discount rate (as a percent)	1.58%

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
In Thousands, unless otherwise specified	Apr. 04, 2015
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	$7,419
Loss included in other comprehensive income (loss)	-18
Balance at the end of the period	$7,401

Fair_Value_of_Financial_Instru6

Fair Value of Financial Instruments (Details 5) (USD $)	3 Months Ended
	Apr. 04, 2015	Jan. 03, 2015
Term Loan Facility
Fair value liabilities reconciliation of changes
Fair value of debt	$84,900,000	$87,400,000
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	18,438,000
Settlements	-4,464,000
Loss recognized in earnings	830,000
Balance at the end of the period	14,804,000
Net loss for the period included in earnings attributable to contingent consideration held at the end of the period:	($830,000)

Balance_Sheet_Details_Details

Balance Sheet Details (Details) (USD $)	Apr. 04, 2015	Jan. 03, 2015
In Thousands, unless otherwise specified
Inventories
Work in progress	$45,822	$40,640
Finished goods	15,256	11,991
Total inventories	$61,078	$52,631

Acquisitions_Details

Acquisitions (Details) (USD $)	3 Months Ended	0 Months Ended
	Apr. 04, 2015	Jan. 30, 2015	Jul. 01, 2013	Jan. 03, 2015
Acquisition
Payment of earn-out for the first annual period	$4,464,000
Purchase price allocation
Goodwill	264,687,000			228,781,000
Bluegiga
Acquisition
Cash consideration		58,000,000
Amount of initial consideration held in escrow by the company as security for breaches of representations and warranties and certain other expressly enumerated matters		9,400,000
Purchase price allocation
Intangible assets		25,450,000
Cash and cash equivalents		1,132,000
Other current assets		6,156,000
Goodwill		35,906,000
Other non-current assets		208,000
Current liabilities		-3,289,000
Non-current deferred tax liabilities, net		-5,090,000
Long-term debt		-2,232,000
Other non-current liabilities		-219,000
Total purchase price		58,022,000
Acquisition-related costs recorded in selling, general and administrative expenses	1,200,000
Discount rate applicable to the cash flows (as a percent)		16.10%
Bluegiga | Developed technology
Purchase price allocation
Intangible assets		12,190,000
Weighted-Average Amortization Period		8 years
Bluegiga | Customer relationships
Purchase price allocation
Intangible assets		6,670,000
Weighted-Average Amortization Period		4 years
Bluegiga | Trademarks
Purchase price allocation
Intangible assets		880,000
Weighted-Average Amortization Period		3 years
Bluegiga | In-process research and development
Purchase price allocation
Intangible assets		5,710,000
Energy Micro
Acquisition
Cash consideration	20,000,000
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
Earn-Out, fair value			14,000,000
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
Payment of earn-out for the first annual period	6,300,000
Earn-out payment representing the Departure Percentage portion and recorded as compensation expense	1,800,000
Remaining Earn-out payment representing additional consideration	$4,500,000

Debt_Details

Debt (Details) (USD $)	3 Months Ended	1 Months Ended
	Apr. 04, 2015	Jul. 31, 2012	Jan. 30, 2015	Sep. 27, 2012
Bluegiga
Debt
Debt in connection with acquisition			$2,232,000
Debt instrument, interest rate, minimum	1.00%
Debt instrument, interest rate, maximum	3.00%
Term Loan Facility
Debt
Maximum borrowing capacity		100,000,000
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
Amount borrowed under the term loan facility				100,000,000
Fixed interest rate percentage	0.76%
Combined interest rate percentage	2.51%
Term Loan Facility
2015	7,500,000
2016	10,000,000
2017	67,500,000
Total debt	85,000,000
Agreement
Debt
Maximum borrowing capacity		230,000,000
Term of debt instrument		5 years
Maximum leverage ratio	2.5
Minimum fixed charge coverage ratio	1.5
Revolving Credit Facility
Debt
Maximum borrowing capacity		130,000,000
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
Term loan facility and revolving credit facility, other than swingline loans | LIBOR | Low end of range
Debt
Interest rate added to the base rate (as a percent)	1.50%
Term loan facility and revolving credit facility, other than swingline loans | LIBOR | High end of range
Debt
Interest rate added to the base rate (as a percent)	2.50%
Term loan facility and revolving credit facility, other than swingline loans | Federal Funds
Debt
Interest rate added to the base rate (as a percent)	0.50%
Term loan facility and revolving credit facility, other than swingline loans | one-month LIBOR
Debt
Interest rate added to the base rate (as a percent)	1.00%
Term loan facility, revolving credit facility, swingline and other loans | Base rate | Low end of range
Debt
Interest rate added to the base rate (as a percent)	0.50%
Term loan facility, revolving credit facility, swingline and other loans | Base rate | High end of range
Debt
Interest rate added to the base rate (as a percent)	1.50%

Stockholders_Equity_Details

Stockholders' Equity (Details) (USD $)	3 Months Ended
Share data in Millions, unless otherwise specified	Apr. 04, 2015	Mar. 29, 2014	Oct. 31, 2014	Jan. 31, 2014	Jan. 31, 2013
Stockholders' Equity
Number of shares of common stock issued	0.7
Components of accumulated other comprehensive loss, net of taxes
Balance at beginning of the period	($82,000)
Other comprehensive income (loss) before reclassifications	-420,000
Amounts reclassified from accumulated other comprehensive loss	91,000
Other comprehensive income (loss)	-329,000	270,000
Balance at end of the period	-411,000
Repurchase of common stock (in shares)	0.2
Repurchase of common stock	10,100,000
Unrealized Gain on Cash Flow Hedge
Components of accumulated other comprehensive loss, net of taxes
Balance at beginning of the period	215,000
Other comprehensive income (loss) before reclassifications	-407,000
Amounts reclassified from accumulated other comprehensive loss	85,000
Other comprehensive income (loss)	-322,000
Balance at end of the period	-107,000
Net Unrealized Losses on Available-For-Sale Securities
Components of accumulated other comprehensive loss, net of taxes
Balance at beginning of the period	-297,000
Other comprehensive income (loss) before reclassifications	-13,000
Amounts reclassified from accumulated other comprehensive loss	6,000
Other comprehensive income (loss)	-7,000
Balance at end of the period	-304,000
High end of range
Stockholders' Equity
Program Amount authorized to repurchase			$100,000,000	$100,000,000	$50,000,000

Stockholders_Equity_Details_2

Stockholders' Equity (Details 2) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Apr. 04, 2015	Mar. 29, 2014
Amounts Reclassified from AOCI
Interest expense	($745)	($798)
Interest income	192	302
Income before income taxes	7,067	9,580
Income tax benefit	-689	-1,470
Net income	6,378	8,110
Reclassifications From Accumulated Other Comprehensive Loss
Amounts Reclassified from AOCI
Income before income taxes	-140	-143
Income tax benefit	49	50
Net income	-91	-93
Unrealized Gain on Cash Flow Hedge | Reclassifications From Accumulated Other Comprehensive Loss
Amounts Reclassified from AOCI
Interest expense	-130	-143
Net Unrealized Losses on Available-For-Sale Securities | Reclassifications From Accumulated Other Comprehensive Loss
Amounts Reclassified from AOCI
Interest income	($10)

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (USD $)	3 Months Ended
	Apr. 04, 2015	Mar. 29, 2014
Stock-based compensation costs
Share based compensation cost before tax	$10,519,000	$9,277,000
Income tax benefit	1,304,000	1,311,000
Share based compensation cost after tax	9,215,000	7,966,000
Total unrecognized compensation costs related to awards	76,700,000
Weighted-average period of recognition of unrecognized compensation costs	2 years 4 months 24 days
Cost of revenues
Stock-based compensation costs
Share based compensation cost before tax	230,000	195,000
Research and development
Stock-based compensation costs
Share based compensation cost before tax	4,795,000	4,241,000
Selling, general and administrative
Stock-based compensation costs
Share based compensation cost before tax	$5,494,000	$4,841,000

Related_Party_Transactions_Det

Related Party Transactions (Details) (USD $)	0 Months Ended	3 Months Ended
	Jul. 01, 2013	Apr. 04, 2015
Related Party Transaction
Payment of the fiscal 2014 earn-out		$4,464,000
Energy Micro
Related Party Transaction
Cash consideration		20,000,000
Payment of the fiscal 2014 earn-out		6,300,000
Contingent consideration		26,700,000
Mr. Forre | Energy Micro
Related Party Transaction
Beneficial ownership percentage	30.00%
Cash consideration	35,000,000	6,100,000
Payment of the fiscal 2014 earn-out		1,900,000
Contingent consideration		8,100,000
Mr. Bogen | Energy Micro
Related Party Transaction
Beneficial ownership percentage	2.00%
Cash consideration	900,000	400,000
Payment of the fiscal 2014 earn-out		100,000
Contingent consideration		500,000
Investment in acquired entity by related party prior to the acquisition	$800,000

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended
	Apr. 04, 2015	Mar. 29, 2014
Income Taxes
Income tax expense	$689,000	$1,470,000
Effective income tax rate (as a percent)	9.70%	15.30%
Gross unrecognized tax benefits	3,800,000
Amount of estimated decrease in unrecognized tax benefits	$600,000