Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income available to common shareholders	$ 29,000	$ 21,619
Unrealized gains on available-for-sale securities arising during the period	26,714	11,362
Reclassification adjustment for gains	(63)	(88)
Reclassification of unrealized gains on held-to-maturity securities to available-for-sale	1,562	0
Other comprehensive income before income taxes	28,213	11,274
Tax effect	6,593	2,643
Other comprehensive income, net of tax	21,620	8,631
Comprehensive Income, Net of Tax	$ 50,620	$ 30,250