Accumulated Other Comprehensive Loss (Reclassifications out of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Sales	$ 863,626	$ 947,248
Tax benefit	(6,755)	(17,691)
Earnings attributable to common and participating shareholders	14,823	37,861
Net of tax	(1,659)	(1,840)
Cash flow hedging activity
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net of tax	(23)	(114)
Amortization of actuarial losses
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification	(2,397)	(2,313)
Prior service costs
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification	(57)	(152)
Pension and other post-retirement effects
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax benefit	818	739
Net of tax	(1,636)	(1,726)
Reclassification out of Accumulated Other Comprehensive Income | Cash flow hedging activity
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax benefit	7	40
Earnings attributable to common and participating shareholders	(23)	(114)
Reclassification out of Accumulated Other Comprehensive Income | Foreign Exchange Contract | Cash flow hedging activity
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Sales	$ (30)	$ (154)