Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 24,593	$ 17,475
Net cumulative translation adjustment and foreign currency exchange hedge, net of tax of $5, and $(146), respectively	(49)	(234)
Net unrealized gain on securities available-for-sale, net of tax of $39 and $32, respectively	63	52
Less: reclassification adjustment for realized gain from securities available-for-sale included in Other Income, net of tax of zero and $(13), respectively		(22)
Net change in unrealized gain on securities available-for-sale, net of tax	63	30
Comprehensive Income	$ 24,607	$ 17,271