Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 54,863	$ 27,623	$ 151,007	$ 66,293
Unrealized holding (losses) gains:
Before tax	(24,763)	(4,142)	(65,305)	54,683
Tax effect	6,837	1,138	18,017	(15,214)
Net of tax	(17,926)	(3,004)	(47,288)	39,469
Reclassification of net losses included in net income:
Before tax	0	14,328	0	13,323
Tax effect	0	(4,012)	0	(3,730)
Net of tax	0	10,316	0	9,593
Net unrealized holding (losses) gains	(17,926)	(13,320)	(47,288)	29,876
Unrealized holding losses:
Before tax	(2,091)	28,614	(6,173)	11,274
Tax effect	577	(7,987)	1,701	(3,162)
Net of tax	(1,514)	20,627	(4,472)	8,112
Reclassification of net losses included in net income:
Before tax	0	(14,285)	0	(14,285)
Tax effect	0	4,000	0	4,000
Net of tax	0	(10,285)	0	(10,285)
Net unrealized holding (losses) gains	(1,514)	10,342	(4,472)	(2,173)
Total other comprehensive (loss) income	(19,440)	(2,978)	(51,760)	27,703
Total comprehensive income (loss)	$ 35,423	$ 24,645	$ 99,247	$ 93,996