Cash, Cash Equivalents and Investments (Details 2) - USD ($) $ in Thousands	Jul. 02, 2016	Jan. 02, 2016
Short-term investments
Amortized Cost	$ 33,975	$ 94,287
Gross Unrealized Gains	770	380
Gross Unrealized Losses	0	(169)
Fair Value	34,745	94,498
Corporate debt securities [Member]
Short-term investments
Amortized Cost	1,998	34,905
Gross Unrealized Gains	0	1
Gross Unrealized Losses	0	(77)
Fair Value	1,998	34,829
Bank certificates of deposit [Member]
Short-term investments
Amortized Cost	6,750	15,049
Gross Unrealized Gains	3	1
Gross Unrealized Losses	0	(4)
Fair Value	6,753	15,046
United States Treasury securities [Member]
Short-term investments
Amortized Cost	21,411	36,372
Gross Unrealized Gains	7	2
Gross Unrealized Losses	0	(88)
Fair Value	21,418	36,286
United States government agency securities [Member]
Short-term investments
Amortized Cost		4,151
Gross Unrealized Gains		1
Gross Unrealized Losses		0
Fair Value		4,152
Commercial paper [Member]
Short-term investments
Amortized Cost	1,497	1,993
Gross Unrealized Gains	1	0
Gross Unrealized Losses	0	0
Fair Value	1,498	1,993
Marketable debt securities [Member]
Short-term investments
Amortized Cost	31,656	92,470
Gross Unrealized Gains	11	5
Gross Unrealized Losses	0	(169)
Fair Value	31,667	92,306
Marketable equity securities [Member]
Short-term investments
Amortized Cost	2,319	1,817
Gross Unrealized Gains	759	375
Gross Unrealized Losses	0	0
Fair Value	$ 3,078	$ 2,192

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
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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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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