Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Convertible preferred stock 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
Balances, Beginning (in shares) at Dec. 31, 2020	223,541,754
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of Series G preferred stock	$ (329,983)
Conversion of Series G preferred stock (in shares)	(223,541,754)
Balances, Beginning at Dec. 31, 2020		$ 4	$ 58,624	$ (351,676)	$ (190)	$ (293,238)
Balances, Beginning (in shares) at Dec. 31, 2020		360,412
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options			10			10
Exercise of stock options (in shares)		11,783
Employee stock compensation			1,159			1,159
Issuance of common stock, net of offering costs		$ 81	133,080			133,161
Issuance of common stock, net of offering costs (in shares)		8,050,000
Reverse stock split			(1)			(1)
Conversion of Series G preferred stock		$ 119	347,069			347,188
Conversion of Series G preferred stock (in shares)		11,929,584
Net loss				(32,508)		(32,508)
Cumulative translation adjustment					(8)	(8)
Balances, Ending at Sep. 30, 2021		$ 204	539,941	(384,184)	(198)	155,763
Balances, Ending (in shares) at Sep. 30, 2021		20,351,779
Balances, Beginning at Jun. 30, 2021	$ 329,983
Balances, Beginning (in shares) at Jun. 30, 2021	223,541,754
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of Series G preferred stock	$ (329,983)
Conversion of Series G preferred stock (in shares)	(223,541,754)
Balances, Beginning at Jun. 30, 2021		$ 4	59,311	(378,051)	(195)	(318,931)
Balances, Beginning (in shares) at Jun. 30, 2021		366,342
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options			8			8
Exercise of stock options (in shares)		5,853
Employee stock compensation			474			474
Issuance of common stock, net of offering costs		$ 81	133,080			133,161
Issuance of common stock, net of offering costs (in shares)		8,050,000
Reverse stock split			(1)			(1)
Conversion of Series G preferred stock		$ 119	347,069			347,188
Conversion of Series G preferred stock (in shares)		11,929,584
Net loss				(6,133)		(6,133)
Cumulative translation adjustment					(3)	(3)
Balances, Ending at Sep. 30, 2021		$ 204	539,941	(384,184)	(198)	155,763
Balances, Ending (in shares) at Sep. 30, 2021		20,351,779
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	80			$ 81
Exercise of stock options (in shares)		121,945				121,945
Proceeds from Employee Stock Purchase Plan		$ 1	294			$ 295
Proceeds from Employee Stock Purchase Plan (shares)		57,681
Employee stock compensation			2,822			2,822
Net loss				(30,892)		(30,892)
Cumulative translation adjustment					(21)	(21)
Balances, Ending at Sep. 30, 2022		$ 206	543,903	(425,646)	(219)	118,244
Balances, Ending (in shares) at Sep. 30, 2022		20,578,963
Balances, Beginning at Jun. 30, 2022		$ 206	542,967	(415,816)	(211)	127,146
Balances, Beginning (in shares) at Jun. 30, 2022		20,576,149
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options			7			7
Exercise of stock options (in shares)		2,814
Employee stock compensation			929			929
Net loss				(9,830)		(9,830)
Cumulative translation adjustment					(8)	(8)
Balances, Ending at Sep. 30, 2022		$ 206	$ 543,903	$ (425,646)	$ (219)	$ 118,244
Balances, Ending (in shares) at Sep. 30, 2022		20,578,963