CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 26, 2015	Sep. 30, 2016	Sep. 26, 2015
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 1,090	$ (884)	$ 7,562	$ 3,928
Currency translation adjustments, net of income tax	1,339	(3,475)	6,165	(8,062)
Comprehensive income (loss)	$ 2,429	$ (4,359)	$ 13,727	$ (4,134)