Consolidated Statements of Comprehensive Income/(Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 30,942	$ 29,590	$ 89,992	$ 69,633
Other comprehensive income/(loss), before tax:
Foreign currency translation and other adjustments	(14,709)	19,249	(16,497)	3,047
Pension/postretirement settlements and curtailments	0	0	0	378
Amortization of pension liability adjustments:
Amortization of prior service credit	(1,119)	(1,114)	(3,356)	(3,342)
Net actuarial loss/ (gain)	1,103	1,244	3,320	3,720
Payments and amortization related to interest rate swaps included in earnings	1,803	1,219	5,049	2,742
Derivative valuation adjustment	722	(385)	369	(12,515)
Income taxes related to items of other comprehensive income/(loss):
Pension/postretirement settlements and curtailments	0	0	0	(113)
Amortization of prior service cost/ (credit)	336	274	1,007	831
Amortization of net actuarial loss/ (gain)	(331)	(306)	(996)	(925)
Payments and amortization related to interest rate swaps included in earnings	(466)	(311)	(1,304)	(701)
Derivative valuation adjustment	(186)	98	(95)	3,200
Comprehensive income/(loss)	18,095	49,558	77,489	65,955
Comprehensive income/(loss) attributable to the noncontrolling interest	(112)	202	(69)	(957)
Comprehensive income/(loss) attributable to the Company	$ 18,207	$ 49,356	$ 77,558	$ 66,912