Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 22,715	$ 17,504	$ 71,546	$ 53,170
Net cumulative translation adjustment and foreign currency exchange hedge, net of tax of $(69), $(96), $(229) and $(334), respectively	(105)	(111)	(420)	(492)
Net unrealized (loss) gain on securities available-for-sale, net of tax of $(4), $(16), $(7) and $16, respectively	(6)	(27)	(12)	30
Less: reclassification adjustment for realized gain from securities available-for-sale included in Other revenues, net of tax of $0, $(7), $0 and $(19), respectively		(12)		(35)
Net change in unrealized (loss) gain on securities available-for-sale, net of tax	(6)	(39)	(12)	(5)
Comprehensive Income	$ 22,604	$ 17,354	$ 71,114	$ 52,673