Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 96,037	$ 74,806	$ 76,016
Net cumulative translation adjustment and foreign currency exchange hedge, net of tax of $(258), $(275) and $(310), respectively	(512)	(399)	(537)
Net unrealized (loss) gain on securities available-for-sale, net of tax of $(111), $(9), and $14, respectively	(180)	(16)	21
Less: reclassification adjustment for realized gain on the sale of securities available-for-sale included in Other Income, net of tax of $(0), $(24) and $(299), respectively		(39)	(474)
Net changed in unrealized (loss) on securities available-for-sale, net of tax	(180)	(55)	(453)
Comprehensive Income	$ 95,345	$ 74,352	$ 75,026