Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Other Comprehensive Income [Abstract]
Net income (loss)	$ (4,382)	$ (6,552)	$ (12,457)	$ (11,951)
Other comprehensive loss:
Unrealized gain on available-for-sale securities	0	7	0	1
Total comprehensive loss	$ (4,382)	$ (6,545)	$ (12,457)	$ (11,950)