Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		$ 311,545
Other comprehensive income (loss)		(5,473)	$ 8,790	$ (9,611)
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	826	1,045	726
Ending Balance		368,255	311,545
Total Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		(17,880)	(27,715)	(18,830)
Ending Balance		(22,527)	(17,880)	(27,715)
Cumulative Translation Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		(8,313)	(17,222)	(9,698)
Other comprehensive income (loss)		(4,172)	8,909	(7,524)
Ending Balance		(12,485)	(8,313)	(17,222)
Pension Liability Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		(9,567)	(10,493)	(9,132)
Other comprehensive income (loss)		(1,301)	(119)	(2,087)
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	826	1,045	726
Ending Balance		$ (10,042)	$ (9,567)	$ (10,493)

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