Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 16,659	$ 2,350
Unrealized gain on securities:
Unrealized holding gain arising during period	(11,785)	11,924
Less: reclassification adjustment for net gain included in net income	(99)
Income tax benefit (expense) related to items of other comprehensive income	3,515	(3,439)
Other comprehensive income (loss), net of tax	(8,369)	8,485
Comprehensive income	$ 8,290	$ 10,835