Accumulated Other Comprehensive Income (Loss) (Details) $ in Thousands	6 Months Ended
	Jun. 29, 2018 USD ($)
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	$ 311,545
Other comprehensive income (loss)	(1,726)
Amounts reclassified from accumulated other comprehensive income (loss)	489	[1]
Ending Balance	324,366
Total Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(17,880)
Ending Balance	(19,117)
Cumulative Translation Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(8,313)
Other comprehensive income (loss)	(1,992)
Ending Balance	(10,305)
Pension Liability Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(9,567)
Other comprehensive income (loss)	266
Amounts reclassified from accumulated other comprehensive income (loss)	489	[1]
Ending Balance	$ (8,812)

[1] The amounts reclassified from other comprehensive income (loss) were included in other income (expense), net in the consolidated statements of operations.