Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 24, 2016	Jun. 30, 2017	Jun. 24, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 20,179	$ 723	$ 34,520	$ (2,516)
Other comprehensive income (loss):
Change in cumulative translation adjustment	591	(21)	689	76
Cash flow hedges:
Change in fair value of derivatives	679	(64)	692	(128)
Adjustment for net gain (loss) realized and included in net income		24	7	50
Total change in unrealized gain (loss) on derivative instruments	679	(40)	699	(78)
Other comprehensive income (loss)	1,270	(61)	1,388	(2)
Comprehensive income (loss)	$ 21,449	$ 662	$ 35,908	$ (2,518)