Accumulated Other Comprehensive Income (AOCI) (Schedule of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 698,683
Ending balance	746,809
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(122,852)	$ (115,976)
Other comprehensive income/(loss) before reclassifications, net of tax	3,038	(23,177)
Pension/postretirement curtailment loss, net of tax	0
Interest expense related to swaps reclassified to the Consolidated Statements of Income, net of tax	0	0
Pension and postretirement liability adjustments reclassified to Consolidated Statements of Income, net of tax	0	0
Adjustment related to prior period change in opening valuation allowance		0
Net current period other comprehensive income	3,038	(23,177)
Ending balance	(119,814)	(139,153)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(49,994)	(47,109)
Other comprehensive income/(loss) before reclassifications, net of tax	9	280
Pension/postretirement curtailment loss, net of tax	265
Interest expense related to swaps reclassified to the Consolidated Statements of Income, net of tax	0	0
Pension and postretirement liability adjustments reclassified to Consolidated Statements of Income, net of tax	284	29
Adjustment related to prior period change in opening valuation allowance		(1,346)
Net current period other comprehensive income	558	(1,037)
Ending balance	(49,436)	(48,146)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(3,135)	4,697
Other comprehensive income/(loss) before reclassifications, net of tax	(9,315)	(8,037)
Pension/postretirement curtailment loss, net of tax	0
Interest expense related to swaps reclassified to the Consolidated Statements of Income, net of tax	2,041	(832)
Pension and postretirement liability adjustments reclassified to Consolidated Statements of Income, net of tax	0	0
Adjustment related to prior period change in opening valuation allowance		0
Net current period other comprehensive income	(7,274)	(8,869)
Ending balance	(10,409)	(4,172)
AOCI Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(175,981)	(158,388)
Other comprehensive income/(loss) before reclassifications, net of tax	(6,268)	(30,934)
Pension/postretirement curtailment loss, net of tax	265
Interest expense related to swaps reclassified to the Consolidated Statements of Income, net of tax	2,041	(832)
Pension and postretirement liability adjustments reclassified to Consolidated Statements of Income, net of tax	284	29
Adjustment related to prior period change in opening valuation allowance		(1,346)
Net current period other comprehensive income	(3,678)	(33,083)
Ending balance	$ (179,659)	$ (191,471)