Consolidated Statements of Comprehensive Income/(Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 52,812	$ 57,265	$ 41,749
Other comprehensive income/(loss), before tax:
Foreign currency translation adjustments	(23,967)	(51,177)	(54,850)
Pension/postretirement settlements and curtailments	51	103	8,377
Pension/postretirement plan remeasurement	(5,498)	(700)	(14,707)
Amortization of pension liability adjustments:
Prior service credit	(4,450)	(4,440)	(4,436)
Net actuarial loss	5,102	5,932	5,329
Payments related to interest rate swaps included in earnings	2,400	1,988	1,914
Derivative valuation adjustment	1,297	(2,961)	(1,724)
Income taxes related to items of other comprehensive income/(loss):
Pension/postretirement settlements and curtailments	(6)		(3,210)
Pension/postretirement plan remeasurement	1,104	78	5,442
Amortization of pension liability adjustments	27	(270)	(330)
Payments related to interest rate swaps included in earnings	(912)	(755)	(746)
Derivative valuation adjustment	(493)	1,125	672
Comprehensive income/(loss)	27,467	6,188	(16,520)
Comprehensive income/(loss) attributable to the noncontrolling interest	77	(9)	178
Comprehensive income/(loss) attributable to the Company	$ 27,390	$ 6,197	$ (16,698)