Accumulated Other Comprehensive Income (AOCI) (Schedule of Accumulated Other Comprehensive Income) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 816,066,000
Ending balance	876,603,000
Translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(83,203,000)	$ (122,852,000)
Other comprehensive income/(loss) before reclassifications, net of tax	(17,124,000)	3,038,000
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
Net current period other comprehensive income	(17,124,000)	3,038,000
Ending balance	(100,327,000)	(119,814,000)
Pension and postretirement liability adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(39,661,000)	(49,994,000)
Other comprehensive income/(loss) before reclassifications, net of tax	627,000	9,000
Pension/postretirement curtailment loss, net of tax		265,000
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	(25,000)	284,000
Net current period other comprehensive income	602,000	558,000
Ending balance	(39,059,000)	(49,436,000)
Derivative adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(9,544,000)	(3,135,000)
Other comprehensive income/(loss) before reclassifications, net of tax	274,000	(9,315,000)
Pension/postretirement curtailment loss, net of tax		0
Interest expense related to swaps reclassified to the Consolidated Statements of Income, net of tax	3,745,000	2,041,000
Pension and postretirement liability adjustments reclassified to Consolidated Statements of Income, net of tax	0	0
Net current period other comprehensive income	4,019,000	(7,274,000)
Ending balance	(5,525,000)	(10,409,000)
Accumulated other comprehensive income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(132,408,000)	(175,981,000)
Other comprehensive income/(loss) before reclassifications, net of tax	(16,223,000)	(6,268,000)
Pension/postretirement curtailment loss, net of tax		265,000
Interest expense related to swaps reclassified to the Consolidated Statements of Income, net of tax	3,745,000	2,041,000
Pension and postretirement liability adjustments reclassified to Consolidated Statements of Income, net of tax	(25,000)	284,000
Net current period other comprehensive income	(12,503,000)	(3,678,000)
Ending balance	$ (144,911,000)	$ (179,659,000)