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 available to common shareholders	$ 20,126	$ 22,371	$ 67,374	$ 66,741
Unrealized (losses) gains on available-for-sale securities arising during the period	(703)	8,199	30,662	33,870
Reclassification adjustment for gains (losses)	0	40	(56)	(69)
Reclassification of unrealized gains on held-to-maturity securities to available-for-sale	0	0	1,562	0
Other comprehensive income before income taxes	(703)	8,239	32,168	33,801
Tax effect	164	(1,932)	(7,518)	(7,924)
Other comprehensive income, net of tax	(539)	6,307	24,650	25,877
Comprehensive Income, Net of Tax	$ 19,587	$ 28,678	$ 92,024	$ 92,618