Condensed Consolidated Statements Of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 2,290	$ 11,462	$ (20,528)	$ (27,032)
Other comprehensive income (loss), net of tax:
Unrealized gain on hedges arising during the period	2,297	4,418	4,141	5,450
Reclassification adjustments for loss on hedges included in net loss	3,383	3,157	10,822	9,651
Income taxes on unrealized gain on hedges	(1,992)	(2,683)	(5,256)	(5,236)
Unrealized gain on hedges, net of tax	3,688	4,892	9,707	9,865
Foreign currency translation gain (loss) arising during the period			14,905	(24,827)
Reclassification adjustment for translation loss realized upon liquidation			0	289
Foreign currency translation gain (loss)	5,513	(3,611)	14,905	(24,538)
Other comprehensive income (loss), net of tax	9,201	1,281	24,612	(14,673)
Comprehensive income (loss)	$ 11,491	$ 12,743	$ 4,084	$ (41,705)