Basis of Condensed Consolidated Financial Statements (AOCI Table) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cumulative foreign currency translation	$ (134,513)		$ (134,513)		$ (122,503)
Cumulative supplemental benefit plans	(8,805)		(8,805)		(8,917)
Net unrecognized losses on interest rate swaps	(73,743)		(73,743)		(35,296)
Reclassification adjustment for gain on terminated interest rate swap included in net income	0	$ (67)	0	$ (67)	(67)
Accumulated other comprehensive loss	$ (217,061)		$ (217,061)		$ (166,783)