Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Comprehensive Deficit
BALANCE, at beginning of period (in shares) at Dec. 31, 2021		54,259,000
BALANCE, at beginning of period at Dec. 31, 2021	$ 100,560	$ 54	$ 352,779	$ (252,273)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash compensation recognized on stock options and employee stock purchase plan ("ESPP")	66		66
Restricted stock grants, net of cancellations (in shares)		1,192,000
Restricted stock grants, net of cancellations	3,783	$ 1	3,782
ESPP shares issued (in shares)		17,000
ESPP shares issued	40		40
Common shares issued in stock offering, net offering costs (in shares)		1,132,000
Common shares issued in stock offering, net of offering costs	1,309	$ 1	1,308
Cancellation of shares for payment of withholding tax (in shares)		(347,000)
Cancellation of shares for payment of withholding tax	(1,084)		(1,084)
Exercise of stock options (in shares)		8,000
Exercise of stock options	16		16
Net loss	(21,307)			(21,307)
BALANCE, at end of period (in shares) at Sep. 30, 2022		56,261,000
BALANCE, at end of period at Sep. 30, 2022	83,383	$ 56	356,907	(273,580)
BALANCE, at beginning of period (in shares) at Jun. 30, 2022		55,120,000
BALANCE, at beginning of period at Jun. 30, 2022	86,928	$ 55	354,641	(267,768)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash compensation recognized on stock options and employee stock purchase plan ("ESPP")	22		22
Restricted stock grants, net of cancellations (in shares)		59,000
Restricted stock grants, net of cancellations	1,074	$ 0	1,074
ESPP shares issued (in shares)		11,000
ESPP shares issued	32		21
Common shares issued in stock offering, net offering costs (in shares)		1,132,000
Common shares issued in stock offering, net of offering costs	1,309	$ 1	1,308
Cancellation of shares for payment of withholding tax (in shares)		(61,000)
Cancellation of shares for payment of withholding tax	(159)		(159)
Net loss	(5,812)			(5,812)
BALANCE, at end of period (in shares) at Sep. 30, 2022		56,261,000
BALANCE, at end of period at Sep. 30, 2022	$ 83,383	$ 56	356,907	(273,580)
BALANCE, at beginning of period (in shares) at Dec. 31, 2022	56,197,910	56,198,000
BALANCE, at beginning of period at Dec. 31, 2022	$ 76,379	$ 56	357,875	(281,552)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash compensation recognized on stock options and employee stock purchase plan ("ESPP")	24		24
Restricted stock grants, net of cancellations (in shares)		1,837,000
Restricted stock grants, net of cancellations	3,292	$ 2	3,290
ESPP shares issued (in shares)		15,000
ESPP shares issued	15		15
Cancellation of shares for payment of withholding tax (in shares)		(245,000)
Cancellation of shares for payment of withholding tax	(381)		(381)
Common shares issued in settlement and prepayment of notes payable (in shares)		12,580,000
Common shares issued in settlement and prepayment of notes payable	15,246	$ 12	15,234
Net loss	$ (17,684)			(17,684)
BALANCE, at end of period (in shares) at Sep. 30, 2023	70,384,838	70,385,000
BALANCE, at end of period at Sep. 30, 2023	$ 76,891	$ 70	376,057	(299,236)
BALANCE, at beginning of period (in shares) at Jun. 30, 2023		65,202,000
BALANCE, at beginning of period at Jun. 30, 2023	74,489	$ 65	368,527	(294,103)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash compensation recognized on stock options and employee stock purchase plan ("ESPP")	6		6
Restricted stock grants, net of cancellations (in shares)		574,000
Restricted stock grants, net of cancellations	1,334	$ 0	1,334
ESPP shares issued (in shares)		7,000
ESPP shares issued	7		7
Cancellation of shares for payment of withholding tax (in shares)		(65,000)
Cancellation of shares for payment of withholding tax	(89)		(89)
Common shares issued in settlement and prepayment of notes payable (in shares)		4,667,000
Common shares issued in settlement and prepayment of notes payable	6,277	$ 5	6,272
Net loss	$ (5,133)			(5,133)
BALANCE, at end of period (in shares) at Sep. 30, 2023	70,384,838	70,385,000
BALANCE, at end of period at Sep. 30, 2023	$ 76,891	$ 70	$ 376,057	$ (299,236)