Accumulated Other Comprehensive Income (AOCI) (Schedule of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 507,523
Ending balance	524,686
Translation adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(133,298)	$ (108,655)
Other comprehensive income/(loss) before reclassifications	10,126	13,114
Pension/postretirement plan remeasurement
Interest expense related to swaps reclassified to the Statement of Income, net of tax
Pension and postretirement liability adjustments reclassified to Statement of Income, net of tax
Net current period other comprehensive income	10,126	13,114
Ending balance	(123,172)	(95,541)
Pension and postretirement liability adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(51,719)	(48,725)
Other comprehensive income/(loss) before reclassifications	(193)	(373)
Pension/postretirement plan remeasurement		(105)
Interest expense related to swaps reclassified to the Statement of Income, net of tax
Pension and postretirement liability adjustments reclassified to Statement of Income, net of tax	164	116
Net current period other comprehensive income	(29)	(362)
Ending balance	(51,748)	(49,087)
Derivative valuation adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	828	(1,464)
Other comprehensive income/(loss) before reclassifications	258	(1,768)
Pension/postretirement plan remeasurement
Interest expense related to swaps reclassified to the Statement of Income, net of tax	372	174
Pension and postretirement liability adjustments reclassified to Statement of Income, net of tax
Net current period other comprehensive income	630	(1,594)
Ending balance	1,458	(3,058)
Total Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(184,189)	(158,844)
Other comprehensive income/(loss) before reclassifications	10,191	10,973
Pension/postretirement plan remeasurement		(105)
Interest expense related to swaps reclassified to the Statement of Income, net of tax	372	174
Pension and postretirement liability adjustments reclassified to Statement of Income, net of tax	164	116
Net current period other comprehensive income	10,727	11,158
Ending balance	$ (173,462)	$ (147,686)