Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 2,350	$ 14,672
Unrealized gain on securities:
Unrealized holding gain arising during period	11,924	6,619
Less: reclassification adjustment for net gain included in net income		(725)
Income tax expense related to items of other comprehensive income	(3,439)	(1,697)
Other comprehensive income, net of tax	8,485	4,197
Comprehensive income	$ 10,835	$ 18,869