Cash, Cash Equivalents and Investments (Details 2) (USD $) In Thousands, unless otherwise specified	Apr. 04, 2015	Jan. 03, 2015
Short-term investments
Amortized Cost	$ 92,533	$ 90,404
Gross Unrealized Gains	117	91
Gross Unrealized Losses	(10)	(50)
Fair Value	92,640us-gaap_AvailableForSaleSecurities	90,445us-gaap_AvailableForSaleSecurities
Corporate debt securities [Member]
Short-term investments
Amortized Cost	33,513	34,919
Gross Unrealized Gains	17	6
Gross Unrealized Losses	(9)	(31)
Fair Value	33,521	34,894
Bank certificates of deposit [Member]
Short-term investments
Amortized Cost	18,300	21,900
Gross Unrealized Gains	7	10
Gross Unrealized Losses	0	0
Fair Value	18,307	21,910
United States Treasury securities [Member]
Short-term investments
Amortized Cost	26,563	19,375
Gross Unrealized Gains	66	12
Gross Unrealized Losses	0	(13)
Fair Value	26,629	19,374
United States government agency securities [Member]
Short-term investments
Amortized Cost	8,159	9,209
Gross Unrealized Gains	2	3
Gross Unrealized Losses	(1)	(4)
Fair Value	8,160	9,208
Commercial paper [Member]
Short-term investments
Amortized Cost	4,181	3,184
Gross Unrealized Gains	18	4
Gross Unrealized Losses	0	(2)
Fair Value	4,199	3,186
Marketable debt securities [Member]
Short-term investments
Amortized Cost	90,716	88,587
Gross Unrealized Gains	110	35
Gross Unrealized Losses	(10)	(50)
Fair Value	90,816	88,572
Marketable equity securities [Member]
Short-term investments
Amortized Cost	1,817	1,817
Gross Unrealized Gains	7	56
Gross Unrealized Losses	0	0
Fair Value	$ 1,824	$ 1,873

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

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-Publisher FASB

-Name Accounting Standards Codification

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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