Stock-Based Compensation Plan (Tables)

12 Months Ended

Dec. 31, 2023

Stock-Based Compensation Plan [Abstract]

Summary of weighted-average assumptions

	2023		2022
Risk-free interest rate	3.42	%	2.43	%
Expected volatility	129	%	127	%
Expected term in years	6.0		6.0
Dividend yield	—	%	—	%

Schedule of option activity under stock-based compensation plans

				Weighted
		Weighted-		Average
		Average		Remaining		Aggregate
		Exercise		Contractual		Intrinsic
	Options	Price		Term		Value
	(in thousands)
Outstanding at December 31, 2022	33	$	233.40		7.9	$	—
Granted	11	$	27.80		9.3
Expired	(1)	$	1,840.00
Outstanding at December 31, 2023	43	$	161.20		7.6	$	—
Vested and expected to vest December 31, 2023	43	$	162.80		7.6	$	—
Exercisable at December 31, 2023	25	$	236.20		6.9	$	—

				Weighted
		Weighted-		Average
		Average		Remaining		Aggregate
		Exercise		Contractual		Intrinsic
	Options	Price		Term		Value
	(in thousands)
Outstanding at December 31, 2021	24	$	291.60		8.4	$	7,800
Granted	10		74.20		9.3
Expired	(1)		119.20
Outstanding at December 31, 2022	33	$	233.40		7.9	$	—
Vested and expected to vest December 31, 2022	32	$	238.00		7.9	$	—
Exercisable at December 31, 2022	16	$	372.40		7.3	$	—