Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 5,932	$ (571)	$ 8,384	$ (1,784)
Net change in unrealized gains (losses) on available-for-sale securities :
Unrealized (losses) gains	(89)	50	(169)	165
Income tax (benefit) effect	20	(10)	(7)	(35)
Total other comprehensive (loss) income, net of tax	(69)	40	(176)	130
Total comprehensive income (loss)	$ 5,863	$ (531)	$ 8,208	$ (1,654)