Accumulated Other Comprehensive Loss (Components of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 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				54,055
Reclassifications to income				6,687
Other comprehensive income (loss)		$ 31,954	$ (30,386)	60,742	$ (112,880)
Ending Balance		(549,045)		(549,045)
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				54,055
Reclassifications to income				0
Other comprehensive income (loss)				54,055
Ending Balance		(365,797)		(365,797)
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				5,516
Other comprehensive income (loss)				5,516
Ending Balance		(176,520)		(176,520)
Reclassifications before taxes, included in net periodic benefit expense		7,061
Reclassifications, income tax expense		1,545
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				1,171
Other comprehensive income (loss)				1,171
Ending Balance		(6,728)		$ (6,728)
Reclassifications before taxes, included in net periodic benefit expense		1,482
Reclassifications income tax, included in interest expense		$ 311

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