Accumulated Other Comprehensive Income (Loss) - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	$ 547,229	$ 450,555
Ending Balance	210,468	532,527
Cumulative Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(23,799)	(36,332)
Other comprehensive income (loss) before reclassifications	(7,342)	3,868
Net other comprehensive income (loss)	(7,342)	3,868
Ending Balance	(31,141)	(32,464)
Unrecognized Net Actuarial Loss and Prior Service Credit, Net
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(11,900)	(11,643)
Amounts reclassified from AOCI, net of tax	354	196
Net other comprehensive income (loss)	354	196
Ending Balance	(11,546)	(11,447)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(35,699)	(47,975)
Other comprehensive income (loss) before reclassifications	(7,342)	3,868
Amounts reclassified from AOCI, net of tax	354	196
Net other comprehensive income (loss)	(6,988)	4,064
Ending Balance	$ (42,687)	$ (43,911)