Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 99,352	$ 150,380	$ 244,176	$ 314,404
Other comprehensive income (loss), net of tax:
Net changes in unrealized gains on AFS debt securities	17,816	29,027	45,269	51,038
Net changes in unrealized losses on cash flow hedge	(1,333)		(1,333)
Foreign currency translation adjustments	(230)	(6,016)	(2,394)	(2,836)
Other comprehensive income	16,253	23,011	41,542	48,202
COMPREHENSIVE INCOME	$ 115,605	$ 173,391	$ 285,718	$ 362,606