CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (1,073)	$ (35,331)
Other comprehensive (loss):
Change in unrealized gain (loss) on available for sale securities, net	(23)	(202)
Total other comprehensive loss	(23)	(202)
Comprehensive loss	$ (1,096)	$ (35,533)