CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 110,143	$ 94,097	$ 320,943	$ 292,872
Other comprehensive (loss) income, net of tax:
Net change in unrealized (losses) gains on available-for-sale investment securities	(4,907)	3,246	12,993	4,439
Foreign currency translation adjustments	(555)	(6,846)	(5,226)	(6,846)
Other comprehensive (loss) income	(5,462)	(3,600)	7,767	(2,407)
COMPREHENSIVE INCOME	$ 104,681	$ 90,497	$ 328,710	$ 290,465