Consolidated Statement of Shareholders' Equity - 9 months ended Oct. 02, 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		1,224,000
Stockholders' Equity, Period Increase (Decrease)		$ 1
Issuance of common stock under stock plans	23,091		23,090
Stock Repurchased During Period, Shares		414,000
Stock repurchased during period, Value	18,941	$ 0		18,941
Stock-based compensation expense	15,883		15,883
Payment of dividends	(18,761)			(18,761)
Net income	111,319			111,319
Net unrealized gain (loss) on cash flow hedges, net of tax of ($76)	(965)				(965)
Reclassification of net realized loss on cash flow hedges	427				427
Net unrealized gain (loss) on available-for-sale investments, net of tax of $481	2,672				2,672
Reclassification of net realized (gain) loss on the sale of available-for-sale investments	(183)				(183)
Foreign currency translation adjustment, net of tax of $254	$ 3,739				3,739
Ending Balance, Shares at Oct. 02, 2016	85,666,000	85,666,000
Ending Balance at Oct. 02, 2016	$ 943,948	$ 171	$ 349,981	$ 640,230	$ (46,434)