CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (4,931)	$ 3,618	$ (12,006)	$ (9,356)
Other comprehensive income (loss):
Unrealized gain (loss) on investments	0	(68)	(37)	57
Comprehensive income (loss)	$ (4,931)	$ 3,550	$ (12,043)	$ (9,299)