Accumulated Other Comprehensive Income (Loss) - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	$ 174,099	$ 547,229
Ending Balance	112,259	210,468
Cumulative Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(16,686)	(23,799)
Other comprehensive income (loss) before reclassifications	(980)	(7,342)
Net other comprehensive income (loss)	(980)	(7,342)
Ending Balance	(17,666)	(31,141)
Unrecognized Net Actuarial Loss and Prior Service Credit, Net
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(13,955)	(11,900)
Amounts reclassified from AOCI, net of tax	205	354
Net other comprehensive income (loss)	205	354
Ending Balance	(13,750)	(11,546)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(30,641)	(35,699)
Other comprehensive income (loss) before reclassifications	(980)	(7,342)
Amounts reclassified from AOCI, net of tax	205	354
Net other comprehensive income (loss)	(775)	(6,988)
Ending Balance	$ (31,416)	$ (42,687)