CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - UNAUDITED - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 17,854	$ 12,410	$ 31,065	$ 23,669
Other comprehensive income:
Unrealized holding gains on securities arising during the period	678	11,265	1,450	10,191
Other comprehensive income before tax	678	11,265	1,450	10,191
Income tax expense related to items of other comprehensive income	198	3,294	423	2,979
Other comprehensive income	480	7,971	1,027	7,212
Total comprehensive income	$ 18,334	$ 20,381	$ 32,092	$ 30,881