Accumulated Other Comprehensive Loss - Rollforward of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 471,814	$ 379,744	$ 341,599	$ 334,619
Other comprehensive (loss) income, before taxes	(26,986)	(801)	(55,622)	(5,263)
Tax expense	(8)	(6)	(25)	(21)
Total other comprehensive loss, net of taxes	(26,994)	(807)	(55,647)	(5,284)
Ending balance	378,998	7,173	378,998	7,173
Foreign Currency Translations
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(53,914)	(27,411)	(25,219)	(22,908)
Other comprehensive (loss) income, before taxes	(27,014)	(812)	(55,709)	(5,315)
Tax expense	0	0	0	0
Total other comprehensive loss, net of taxes	(27,014)	(812)	(55,709)	(5,315)
Ending balance	(80,928)	(28,223)	(80,928)	(28,223)
Accumulated (Loss) Gain on Retirement Plan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(972)	(993)	(1,014)	(1,019)
Other comprehensive (loss) income, before taxes	28	11	87	52
Tax expense	(8)	(6)	(25)	(21)
Total other comprehensive loss, net of taxes	20	5	62	31
Ending balance	(952)	(988)	(952)	(988)
Accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(54,886)	(28,404)	(26,233)	(23,927)
Total other comprehensive loss, net of taxes	(26,994)	(807)	(55,647)	(5,284)
Ending balance	$ (81,880)	$ (29,211)	$ (81,880)	$ (29,211)