Repurchase of Common Stock (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Repurchase of Common Stock [Abstract]
Amount repurchased under Board-approved share repurchase program	$ 65,000	$ 25,000	$ 140,000	$ 75,000
Amount repurchased in connection with the vesting of employee restricted stock grants	292	300	2,940	5,094
Total amount repurchased	65,292	$ 25,300	142,940	$ 80,094
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 325,000		$ 325,000