Accumulated Other Comprehensive Loss (Components of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	[1]			$ (609,787)
2019 components of other comprehensive income (loss):
Before reclassifications to income and retained earnings				36,927
Reclassifications to income				10,033
Other comprehensive income (loss)		$ (13,782)	$ 37,355	46,960	$ (75,525)
Ending Balance		(562,827)		(562,827)
Foreign Currency Translation Gains (Losses)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance				(419,852)
2019 components of other comprehensive income (loss):
Before reclassifications to income and retained earnings				36,927
Reclassifications to income				0
Other comprehensive income (loss)				36,927
Ending Balance		(382,925)		(382,925)
Retirement and Postretirement Benefit Plan Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance				(182,036)
2019 components of other comprehensive income (loss):
Before reclassifications to income and retained earnings				0
Reclassifications to income				8,277
Other comprehensive income (loss)				8,277
Ending Balance		(173,759)		(173,759)
Reclassifications before taxes, included in net periodic benefit expense				10,598
Reclassifications, income tax expense				2,321
Deferred Loss on Interest Rate Derivative Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance				(7,899)
2019 components of other comprehensive income (loss):
Before reclassifications to income and retained earnings				0
Reclassifications to income				1,756
Other comprehensive income (loss)				1,756
Ending Balance		$ (6,143)		(6,143)
Reclassifications before taxes, included in net periodic benefit expense				2,223
Reclassifications, income tax expense				$ 467

[1] Reclassified to conform to current presentation (see Note A).