Other Comprehensive Loss - Related Tax Effects Allocated to Each Component of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Equity [Abstract]
Amortization of actuarial losses, before tax amount	$ (1,179)	$ (2,186)	$ (2,284)	$ (380)
Derivative instruments, before tax amount	1,167	(515)	(878)	(193)
Cumulative translation adjustment, before tax amount	2,628	(3,388)	(257)	(3,048)
Total other comprehensive income (loss), before tax amount	2,616	(6,089)	(3,419)	(3,621)
Amortization of actuarial losses, tax expense	222	91	434	(628)
Derivative instrument, tax expense	(274)	0	97	0
Cumulative translation adjustment, tax expense	0	0	0	0
Total other comprehensive income (loss), tax expense	(52)	91	531	(628)
Amortization of actuarial losses, after tax amount	(957)	(2,095)	(1,850)	(1,008)
Derivative instrument, after tax amount	893	(515)	(781)	(193)
Cumulative translation adjustment, after tax amount	2,628	(3,388)	(257)	(3,048)
Other comprehensive (loss) income	$ 2,564	$ (5,998)	$ (2,888)	$ (4,249)