CONDENSED CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (unaudited) - USD ($) $ in Thousands	Total	Convertible Preferred Stock	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Convertible Preferred Stock Beginning balance, Shares at Dec. 31, 2020		17,031,887
Convertible Preferred Stock Beginning balance at Dec. 31, 2020		$ 281,342
Beginning balance, Shares at Dec. 31, 2020			1,200,335
Beginning balance at Dec. 31, 2020	$ (253,891)		$ 2	$ (51)	$ 9,703		$ (263,545)
Exercise of stock options	33				33
Exercise of stock options, Shares			12,797
Stock-based compensation	494				494
Net loss	(10,906)						(10,906)
Convertible Preferred Stock Ending balance, Shares at Mar. 31, 2021		17,031,887
Convertible Preferred Stock Ending balance at Mar. 31, 2021		$ 281,342
Ending balance, Shares at Mar. 31, 2021			1,213,132
Ending balance at Mar. 31, 2021	(264,270)		$ 2	(51)	10,230		(274,451)
Convertible Preferred Stock Beginning balance, Shares at Dec. 31, 2020		17,031,887
Convertible Preferred Stock Beginning balance at Dec. 31, 2020		$ 281,342
Beginning balance, Shares at Dec. 31, 2020			1,200,335
Beginning balance at Dec. 31, 2020	(253,891)		$ 2	(51)	9,703		(263,545)
Net loss	(22,055)
Convertible Preferred Stock Ending balance, Shares at Jun. 30, 2021		17,031,887
Convertible Preferred Stock Ending balance at Jun. 30, 2021		$ 281,342
Ending balance, Shares at Jun. 30, 2021			1,223,346
Ending balance at Jun. 30, 2021	(274,950)		$ 2	(51)	10,699		(285,600)
Convertible Preferred Stock Beginning balance, Shares at Mar. 31, 2021		17,031,887
Convertible Preferred Stock Beginning balance at Mar. 31, 2021		$ 281,342
Beginning balance, Shares at Mar. 31, 2021			1,213,132
Beginning balance at Mar. 31, 2021	(264,270)		$ 2	(51)	10,230		(274,451)
Exercise of stock options	56				56
Exercise of stock options, Shares			10,214
Stock-based compensation	413				413
Net loss	(11,149)						(11,149)
Convertible Preferred Stock Ending balance, Shares at Jun. 30, 2021		17,031,887
Convertible Preferred Stock Ending balance at Jun. 30, 2021		$ 281,342
Ending balance, Shares at Jun. 30, 2021			1,223,346
Ending balance at Jun. 30, 2021	(274,950)		$ 2	(51)	10,699		(285,600)
Beginning balance, Shares at Dec. 31, 2021			26,336,536
Beginning balance at Dec. 31, 2021	72,063		$ 26	(51)	384,132		(312,044)
Employee stock plans	242				242
Employee stock plans, Shares			82,572
Stock-based compensation	1,394				1,394
Net loss	(15,522)						(15,522)
Ending balance, Shares at Mar. 31, 2022			26,419,108
Ending balance at Mar. 31, 2022	58,177		$ 26	(51)	385,768		(327,566)
Beginning balance, Shares at Dec. 31, 2021			26,336,536
Beginning balance at Dec. 31, 2021	$ 72,063		$ 26	(51)	384,132		(312,044)
Exercise of stock options, Shares	69,556
Unrealized loss on short-term investments	$ (42)
Net loss	(30,659)
Ending balance, Shares at Jun. 30, 2022			26,569,220
Ending balance at Jun. 30, 2022	45,034		$ 27	(51)	387,803	$ (42)	(342,703)
Beginning balance, Shares at Mar. 31, 2022			26,419,108
Beginning balance at Mar. 31, 2022	58,177		$ 26	(51)	385,768		(327,566)
Employee stock plans	9		$ 1		8
Employee stock plans, Shares			150,112
Stock-based compensation	1,954				1,954
Revaluation of warrants	73				73
Unrealized loss on short-term investments	(42)					(42)
Net loss	(15,137)						(15,137)
Ending balance, Shares at Jun. 30, 2022			26,569,220
Ending balance at Jun. 30, 2022	$ 45,034		$ 27	$ (51)	$ 387,803	$ (42)	$ (342,703)