Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 19,136	$ 23,353	$ 62,215	$ 58,101
Other comprehensive income:
Unrealized gain (loss) on debt securities, net of tax	(1,876)	734	(6,033)	7,701
Comprehensive income	$ 17,260	$ 24,087	$ 56,182	$ 65,802