Accumulated Other Comprehensive Income (Loss) (Details) $ in Thousands	9 Months Ended
	Sep. 28, 2018 USD ($)
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	$ 311,545
Other comprehensive income (loss)	(2,232)
Amounts reclassified from accumulated other comprehensive income (loss)	728	[1]
Ending Balance	359,676
Total Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(17,880)
Ending Balance	(19,384)
Cumulative Translation Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(8,313)
Other comprehensive income (loss)	(2,482)
Ending Balance	(10,795)
Pension Liability Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(9,567)
Other comprehensive income (loss)	250
Amounts reclassified from accumulated other comprehensive income (loss)	728	[1]
Ending Balance	$ (8,589)

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