Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Statement Of Comprehensive Income [Abstract]
Net unrealized income (loss) on hedging derivatives, tax	$ 300	$ (300)	$ (700)	$ 600
Reclassification adjustment for loss on settlement of hedging derivatives included in net income, tax effect	0	1,200	300	4,800
Foreign currency translation gain (loss) tax	$ 0	$ 0	$ 0	$ 0