Consolidated Statements Of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Consolidated Statements Of Comprehensive Income (Loss) [Abstract]
Unrealized gain (loss) on interest rate swap contracts, deferred income tax expense (benefit)	$ 535	$ (2,222)	$ 1,895	$ (8,112)
Foreign currency translation adjustments, deferred income tax expense (benefit)	$ 72	$ (1,166)	$ (1,311)	$ (1,991)