Basis of Condensed Consolidated Financial Statements (AOCI Table) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cumulative foreign currency translation	$ (124,064)	$ (129,406)
Cumulative supplemental benefit plans	(5,107)	(4,958)
Net unrecognized losses on interest rate swaps	(13,590)	(1,384)
Accumulated other comprehensive loss	$ (142,761)	$ (135,748)

Accumulated adjustment, net of tax, that results from the process of translating subsidiary financial statements and foreign equity investments into the reporting currency from the functional currency of the reporting entity, net of reclassification of realized foreign currency translation gains or losses.

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