Unaudited Condensed Consolidated Statements 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	$ 63,444	$ 52,392	$ 106,783	$ 101,524
Other Comprehensive Income, Net of Tax
Unrealized gains on available-for-sale securities	41,014	29,877	121,569	76,329
Reclassification adjustment for gains included in net income	(128)	(134)	(990)	(355)
Net unrealized gains on available-for-sale securities	40,886	29,743	120,579	75,974
Tax effect	(10,360)	(7,537)	(30,555)	(19,252)
Net of tax amount	30,526	22,206	90,024	56,722
Unrealized losses on derivatives used for cash flow hedges	(456)	(3,820)	(456)	(5,654)
Reclassification adjustment for losses included in net income	0	278	0	501
Net unrealized losses on derivatives used for cash flow hedges	(456)	(3,542)	(456)	(5,153)
Tax effect	115	897	115	1,306
Net of tax amount	(341)	(2,645)	(341)	(3,847)
Total other comprehensive income, net of tax	30,185	19,561	89,683	52,875
Total Comprehensive Income	$ 93,629	$ 71,953	$ 196,466	$ 154,399