Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 17,475	$ 15,326
Net cumulative translation adjustment and foreign currency exchange hedge, net of tax of $(146) and $73, respectively	(234)	116
Net unrealized gain (loss) on securities available-for-sale, net of tax of $32, and $(19), respectively	52	(32)
Less: reclassification adjustment for realized gain from securities available-for-sale included in Other Income, net of tax of $(13) and $(299), respectively	(22)	(474)
Net changed in unrealized gain (loss) on securities available-for-sale, net of tax	30	(506)
Comprehensive Income	$ 17,271	$ 14,936