CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 29,408	$ 7,899
Other comprehensive income/(loss), before tax:
Foreign currency translation and other adjustments	(2,152)	17,505
Amortization of pension liability adjustments:
Prior service credit	(1,105)	(1,114)
Net actuarial loss	1,121	1,297
Payments and amortization related to interest rate swaps included in earnings	(452)	180
Derivative valuation adjustment	(3,377)	5,715
Income taxes related to items of other comprehensive income/(loss):
Amortization of pension liability adjustment	(5)	(55)
Payments related to interest rate swaps included in earnings	115	(43)
Derivative valuation adjustment	863	(1,372)
Comprehensive income	24,416	30,012
Comprehensive income/(loss) attributable to the noncontrolling interest	210	230
Comprehensive income attributable to the Company	$ 24,206	$ 29,782