Consolidated Statement of Shareholders' Equity - 6 months ended Jul. 03, 2016 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning Balance, Shares at Dec. 31, 2015	84,856,000	84,856,000
Beginning Balance at Dec. 31, 2015	$ 825,667	$ 170	$ 311,008	$ 566,613	$ (52,124)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under stock plans, shares		461,000
Issuance of common stock under stock plans	8,700		8,700
Stock Repurchased During Period, Shares		208,000
Stock repurchased during period, Value	8,718	$ 0		8,718
Stock-based compensation expense	11,261		11,261
Payment of dividends	(12,335)			(12,335)
Net income	57,644			57,644
Net unrealized gain (loss) on cash flow hedges, net of tax of ($97)	(879)				(879)
Reclassification of net realized loss on cash flow hedges	186				186
Net unrealized gain (loss) on available-for-sale investments, net of tax of $510	2,632				2,632
Reclassification of net realized (gain) loss on the sale of available-for-sale investments	(128)				(128)
Foreign currency translation adjustment, net of tax of $174	$ 2,614				2,614
Ending Balance, Shares at Jul. 03, 2016	85,109,000	85,109,000
Ending Balance at Jul. 03, 2016	$ 886,644	$ 170	$ 330,969	$ 603,204	$ (47,699)