Condensed Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common stock	Treasury stock	Additional paid-in capital	Accumulated deficit
Balance, beginning of year at Dec. 31, 2021	$ 40,857	$ 62	$ (260)	$ 662,399	$ (621,344)
Balance, beginning of year (in shares) at Dec. 31, 2021		6,224,209	7,273
Employee stock-based compensation expense	2,196			2,196
Employee stock purchase program (ESPP)	329			329
Employee stock purchase program (ESPP) (in shares)		13,958
Vested RSUs (in shares)		26,533
Shares repurchased for tax withholding on vesting RSUs (shares)		(9,407)
Shares repurchased for tax withholding on vesting RSUs	(255)			(255)
Net loss	(18,041)				(18,041)
Balance, end of year at Mar. 31, 2022	25,086	$ 62	$ (260)	664,669	(639,385)
Balance, end of year (in shares) at Mar. 31, 2022		6,255,293	7,273
Balance, beginning of year at Dec. 31, 2021	40,857	$ 62	$ (260)	662,399	(621,344)
Balance, beginning of year (in shares) at Dec. 31, 2021		6,224,209	7,273
Derivative liability reclassified to equity	0
Net loss	(36,345)
Balance, end of year at Jun. 30, 2022	8,669	$ 62	$ (260)	666,556	(657,689)
Balance, end of year (in shares) at Jun. 30, 2022		6,279,621	7,273
Balance, beginning of year at Mar. 31, 2022	25,086	$ 62	$ (260)	664,669	(639,385)
Balance, beginning of year (in shares) at Mar. 31, 2022		6,255,293	7,273
Employee stock-based compensation expense	2,062			2,062
Vested RSUs	(0)
Vested RSUs (in shares)		33,077
Shares repurchased for tax withholding on vesting RSUs (shares)		(8,749)
Shares repurchased for tax withholding on vesting RSUs	(175)			(175)
Net loss	(18,304)				(18,304)
Balance, end of year at Jun. 30, 2022	8,669	$ 62	$ (260)	666,556	(657,689)
Balance, end of year (in shares) at Jun. 30, 2022		6,279,621	7,273
Balance, beginning of year at Dec. 31, 2022	(409)	$ 107	$ (260)	694,395	(694,651)
Balance, beginning of year (in shares) at Dec. 31, 2022		10,709,716	7,273
Derivative liability reclassified to equity	880			880
Employee stock-based compensation expense	1,722			1,722
Exercise of warrants		$ 3		(3)
Exercise of warrants (in shares)		290,315
Employee stock purchase program (ESPP)	256	$ 1		255
Employee stock purchase program (ESPP) (in shares)		146,227
Vested RSUs		$ 1		(1)
Vested RSUs (in shares)		70,017
Shares repurchased for tax withholding on vesting RSUs (shares)		(25,034)
Shares repurchased for tax withholding on vesting RSUs	(40)			(40)
Net loss	(12,892)				(12,892)
Balance, end of year at Mar. 31, 2023	(10,483)	$ 112	$ (260)	697,208	(707,543)
Balance, end of year (in shares) at Mar. 31, 2023		11,191,241	7,273
Balance, beginning of year at Dec. 31, 2022	(409)	$ 107	$ (260)	694,395	(694,651)
Balance, beginning of year (in shares) at Dec. 31, 2022		10,709,716	7,273
Derivative liability reclassified to equity	880
Net loss	(22,369)
Balance, end of year at Jun. 30, 2023	(18,632)	$ 113	$ (260)	698,535	(717,020)
Balance, end of year (in shares) at Jun. 30, 2023		11,261,906	7,273
Balance, beginning of year at Mar. 31, 2023	(10,483)	$ 112	$ (260)	697,208	(707,543)
Balance, beginning of year (in shares) at Mar. 31, 2023		11,191,241	7,273
Employee stock-based compensation expense	1,338			1,338
Employee stock purchase program (ESPP)	(3)			(3)
Employee stock purchase program (ESPP) (in shares)		(1,780)
Vested RSUs	0	$ 1		(1)
Vested RSUs (in shares)		78,661
Shares repurchased for tax withholding on vesting RSUs (shares)		(6,216)
Shares repurchased for tax withholding on vesting RSUs	(7)			(7)
Net loss	(9,477)				(9,477)
Balance, end of year at Jun. 30, 2023	$ (18,632)	$ 113	$ (260)	$ 698,535	$ (717,020)
Balance, end of year (in shares) at Jun. 30, 2023		11,261,906	7,273