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 Income And Comprehensive Income [Abstract]
Net income	$ 76,016	$ 60,069	$ 47,704
Net cumulative translation adjustment and foreign currency exchange hedge, net of tax of $(310), $(390) and $(440), respectively	(537)	(748)	(634)
Net unrealized gain (loss) on securities available-for-sale, net of tax of $14, $(244), and $271, respectively	21	(342)	403
Less: reclassification adjustment for realized gain on the sale of securities available-for-sale included in Other Income, net of tax of $(299), $(76) and $0, respectively	(474)	(121)
Net changed in unrealized (loss) gain on securities available-for-sale, net of tax	(453)	(463)	403
Comprehensive Income	$ 75,026	$ 58,858	$ 47,473