Consolidated Statement of Shareholders' Equity - 6 months ended Jul. 02, 2017 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning Balance, Shares at Dec. 31, 2016	85,939,000	85,939,000
Beginning Balance at Dec. 31, 2016	$ 962,599	$ 172	$ 375,030	$ 643,825	$ (56,428)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under stock plans, shares		1,365,000
Stockholders' Equity, Period Increase (Decrease)		$ 3
Issuance of common stock under stock plans	35,050		35,047
Stock Repurchased During Period, Shares		732,000
Stock repurchased during period, Value	62,343	$ 2		62,341
Stock-based compensation expense	15,329		15,329
Payment of dividends	(13,864)			(13,864)
Net income	101,727			101,727
Net unrealized gain (loss) on cash flow hedges, net of tax of $3	(12)				(12)
Reclassification of net realized loss on cash flow hedges	35				35
Net unrealized gain (loss) on available-for-sale investments, net of tax of $150	818				818
Reclassification of net realized (gain) loss on the sale of available-for-sale investments	(107)				(107)
Foreign currency translation adjustment, net of tax of $0	$ 12,744				12,744
Ending Balance, Shares at Jul. 02, 2017	86,572,000	86,572,000
Ending Balance at Jul. 02, 2017	$ 1,051,976	$ 173	$ 425,406	$ 669,347	$ (42,950)