CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 40,125	$ 28,005	$ 103,792	$ 65,747
Other comprehensive income/(loss), before tax:
Foreign currency translation and other adjustments	(22,041)	(7,847)	(24,243)	(21,193)
Pension/postretirement curtailment		(232)		(750)
Amortization of pension liability adjustments:
Prior service credit	(1,105)	(1,114)	(3,315)	(3,341)
Net actuarial loss	1,118	1,294	3,357	3,882
Payments and amortization related to interest rate swaps included in earnings	(245)	(96)	(1,117)	138
Derivative valuation adjustment	(1,532)	1,777	(10,796)	9,703
Income taxes related to items of other comprehensive income/(loss):
Pension/postretirement curtailment		70		225
Amortization of pension liability adjustment	(4)	(54)	(13)	(162)
Payments related to interest rate swaps included in earnings	62	23	285	(33)
Derivative valuation adjustment	392	(427)	2,759	(2,329)
Comprehensive income	16,770	21,399	70,709	51,887
Comprehensive income attributable to the noncontrolling interest	103	264	520	446
Comprehensive income attributable to the Company	$ 16,667	$ 21,135	$ 70,189	$ 51,441