Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement Of Consolidated Comprehensive Income [Abstract]
Net income	$ 80,513	$ 90,137	$ 94,072
Other comprehensive income, before tax and net of reclassification adjustments:
Foreign currency translation adjustment	1,332	2,231	(1,236)
Unrealized gain (loss) on securities available-for-sale	(538)	56	(1,017)
Unrealized gain (loss) on derivative instruments	1,238	3,152	(305)
Other comprehensive income (loss), before tax	2,032	5,439	(2,558)
Tax provision related to items of other comprehensive income	(326)	(1,095)	(232)
Other comprehensive income (loss), net of tax	1,706	4,344	(2,790)
Comprehensive income	$ 82,219	$ 94,481	$ 91,282