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