Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 82,734	$ 95,262	$ 126,333
Other comprehensive income, before tax and net of reclassification adjustments:
Foreign currency translation adjustment	(5,697)	(19,240)	(21,218)
Unrealized (loss) gain on securities available-for-sale	210	701	(380)
Unrealized gain on derivative instruments	13,166	(19,012)	7,692
Other comprehensive income (loss), before tax	7,679	(37,551)	(13,906)
Tax provision related to items of other comprehensive income	4,210	(11,125)	308
Other comprehensive income (loss), net of tax	3,469	(26,426)	(14,214)
Comprehensive income	$ 86,203	$ 68,836	$ 112,119