Consolidated Statement of Comprehensive Income - Unaudited - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 224,742	$ 99,352	$ 429,736	$ 244,176
Other comprehensive income (loss), net of tax:
Net changes in unrealized gains (losses) on AFS debt securities	73,049	17,816	(60,399)	45,269
Net changes in unrealized gains (losses) on cash flow hedges	68	(1,333)	500	(1,333)
Foreign currency translation adjustments	2,234	(230)	885	(2,394)
Other comprehensive income (loss)	75,351	16,253	(59,014)	41,542
COMPREHENSIVE INCOME	$ 300,093	$ 115,605	$ 370,722	$ 285,718