Unaudited Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 77,757	$ 51,610	$ 184,540	$ 153,134
Other Comprehensive Income, Net of Tax
Unrealized gains on available-for-sale securities	1,693	11,113	123,262	87,442
Reclassification adjustment for gains included in net income	(24)	(13,811)	(1,014)	(14,166)
Net unrealized gains (losses) on available-for-sale securities	1,669	(2,698)	122,248	73,276
Tax effect	(424)	684	(30,979)	(18,568)
Net of tax amount	1,245	(2,014)	91,269	54,708
Unrealized losses on derivatives used for cash flow hedges	(76)	(1,393)	(532)	(7,047)
Reclassification adjustment for losses included in net income	0	10,315	0	10,816
Net unrealized (losses) gains on derivatives used for cash flow hedges	(76)	8,922	(532)	3,769
Tax effect	20	(2,261)	135	(955)
Net of tax amount	(56)	6,661	(397)	2,814
Total other comprehensive income, net of tax	1,189	4,647	90,872	57,522
Total Comprehensive Income	$ 78,946	$ 56,257	$ 275,412	$ 210,656