Derivative Financial Instruments (Derivative Gains Included In Accumulated Other Comprehensive Loss (AOCL) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Derivative Gains Included in AOCI [Roll Forward]
Beginning balance	$ (25,165)	$ (34,804)	$ (33,755)	$ (34,776)
Net gain (loss) on cash flow hedges	6,852	(228)	13,963	(1,735)
Reclassification of net loss (gain) on cash flow hedges to income	740	740	2,219	2,219
Ending balance	$ (17,573)	$ (34,292)	$ (17,573)	$ (34,292)

Amount after tax of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss).

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