Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Convertible preferred stock	Common stock	Additional paid-in capital	Accumulated deficit	Accumulated and other comprehensive loss	Total
Balances, Beginning at Dec. 31, 2020	$ 329,983	$ 4	$ 58,624	$ (351,676)	$ (190)	$ (293,238)
Balances, Beginning (in shares) at Dec. 31, 2020	223,541,754,000	360,412
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options			2			2
Exercise of stock options (in shares)		5,930
Employee stock compensation			685			685
Net loss				(26,375)		(26,375)
Cumulative translation adjustment					(5)	(5)
Balances, Ending at Jun. 30, 2021	$ 329,983	$ 4	59,311	(378,051)	(195)	(318,931)
Balances, Ending (in shares) at Jun. 30, 2021	223,541,754	366,342
Balances, Beginning at Mar. 31, 2021	$ 329,983	$ 4	58,687	(360,303)	(194)	(301,806)
Balances, Beginning (in shares) at Mar. 31, 2021	223,541,754	365,274
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)		1,068
Employee stock compensation			624			624
Net loss				(17,748)		(17,748)
Cumulative translation adjustment					(1)	(1)
Balances, Ending at Jun. 30, 2021	$ 329,983	$ 4	59,311	(378,051)	(195)	(318,931)
Balances, Ending (in shares) at Jun. 30, 2021	223,541,754	366,342
Balances, Beginning at Dec. 31, 2021		$ 204	540,707	(394,754)	(198)	145,959
Balances, Beginning (in shares) at Dec. 31, 2021		20,399,337
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options		$ 1	73			$ 74
Exercise of stock options (in shares)		119,131				119,131
Proceeds from Employee Stock Purchase Plan		$ 1	294			$ 295
Proceeds from Employee Stock Purchase Plan (shares)		57,681
Employee stock compensation			1,893			1,893
Net loss				(21,062)		(21,062)
Cumulative translation adjustment					(13)	(13)
Balances, Ending at Jun. 30, 2022		$ 206	542,967	(415,816)	(211)	127,146
Balances, Ending (in shares) at Jun. 30, 2022		20,576,149
Balances, Beginning at Mar. 31, 2022		$ 205	541,547	(404,745)	(204)	136,803
Balances, Beginning (in shares) at Mar. 31, 2022		20,486,971
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options			26			26
Exercise of stock options (in shares)		31,497
Proceeds from Employee Stock Purchase Plan		$ 1	294			295
Proceeds from Employee Stock Purchase Plan (shares)		57,681
Employee stock compensation			1,100			1,100
Net loss				(11,071)		(11,071)
Cumulative translation adjustment					(7)	(7)
Balances, Ending at Jun. 30, 2022		$ 206	$ 542,967	$ (415,816)	$ (211)	$ 127,146
Balances, Ending (in shares) at Jun. 30, 2022		20,576,149