Summary of Significant Accounting Policies - The Balances in the Company's Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 97,703	$ 146,571	$ 235,507
Total other comprehensive income (loss)	4,936	(27,422)	(14,115)
Ending balance	93,033	97,703	146,571
Foreign Currency [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(37,447)	(9,825)	3,493
Other comprehensive income (loss) before reclassifications	5,105	(17,131)	(13,318)
Amounts reclassified from accumulated other comprehensive income, net of tax	0	(10,491)	0
Total other comprehensive income (loss)	5,105	(27,622)	(13,318)
Ending balance	(32,342)	(37,447)	(9,825)
Defined Benefit Pension Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(1,663)	(1,863)	(1,066)
Other comprehensive income (loss) before reclassifications	(222)	144	(826)
Amounts reclassified from accumulated other comprehensive income, net of tax	53	56	29
Total other comprehensive income (loss)	(169)	200	(797)
Ending balance	(1,832)	(1,663)	(1,863)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(39,110)	(11,688)	2,427
Other comprehensive income (loss) before reclassifications	4,883	(16,987)	(14,144)
Amounts reclassified from accumulated other comprehensive income, net of tax	53	(10,435)	29
Total other comprehensive income (loss)	4,936	(27,422)	(14,115)
Ending balance	$ (34,174)	$ (39,110)	$ (11,688)