CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 5,377	$ 13,554	$ 20,305	$ 27,197
Foreign currency translation adjustment	(5,729)	8,731	5,197	(19,250)
Derivative instruments designated as cash flow hedges:
Unrealized gain (loss) on derivative instruments held at period end, net of tax (Note 6)		(160)		(160)
Unrealized gain (loss) reclassified into earnings (Note 6)	5	(124)	11	94
Pension and postretirement benefit plans reclassified into earnings, net of tax (Note 6):
Amortization of loss	36	262	71	531
Other comprehensive income (loss)	(5,688)	8,709	5,279	(18,785)
Comprehensive income (loss)	$ (311)	$ 22,263	$ 25,584	$ 8,412