Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 172,852	$ 148,089	$ 126,172
Net cumulative translation adjustment and foreign currency exchange hedge, net of tax of $1,290, $(2,807) and $5,407, respectively	(2,078)	2,236	(7,037)
Net unrealized (loss) gain on securities available-for-sale, net of tax of $(23), $(39), and $24, respectively	(90)	(234)	38
Comprehensive income	$ 170,684	$ 150,091	$ 119,173