Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders’ (Deficit) Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Series 1 Preferred	Series 1 Preferred Preferred Stock
Preferred stock, beginning balance (in shares) at Dec. 31, 2019								538,000
Preferred stock, beginning balance at Dec. 31, 2019								$ 21,468
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of redeemable convertible preferred stock into common stock (in shares)		(860,000)					(86,000)	(86,000)
Conversion of redeemable convertible preferred stock into common stock	$ 3,432	$ 9		$ 3,423				$ (3,432)
Preferred stock, ending balance (in shares) at Dec. 31, 2020								452,000
Preferred stock, ending balance at Dec. 31, 2020	18,036							$ 18,036
Balance, beginning of period (in shares) at Dec. 31, 2019		5,076,593	67,746
Balance, beginning of period at Dec. 31, 2019	(26,217)	$ 507	$ (5,056)	511,684	$ (533,025)	$ (327)
Increase (Decrease) in Stockholders' Equity
Share-based compensation	5,031			5,031
1-for-10 Reverse Stock Split	0	$ (457)		457
Issuance of common stock - Employee Stock Purchase Plan (in shares)		14,975
Issuance of common stock - Employee Stock Purchase Plan	78			78
Issuance of common stock upon vesting of restricted stock units (in shares)		1,406
Issuance of common stock and pre-funded warrants exercise, net of issuance costs (in shares)		2,432,676
Issuance of common stock and pre-funded warrants exercise, net of issuance costs	22,913	$ 25		22,888
Conversion of redeemable convertible preferred stock into common stock (in shares)		860,000					86,000	86,000
Conversion of redeemable convertible preferred stock into common stock	3,432	$ 9		3,423				$ (3,432)
Comprehensive loss	(7,734)				(7,722)	(12)
Balance, end of period (in shares) at Dec. 31, 2020		8,385,650	67,746
Balance, end of period at Dec. 31, 2020	(2,497)	$ 84	$ (5,056)	543,561	(540,747)	(339)
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of redeemable convertible preferred stock into common stock (in shares)							0
Preferred stock, ending balance (in shares) at Dec. 31, 2021								452,000
Preferred stock, ending balance at Dec. 31, 2021	18,036							$ 18,036
Increase (Decrease) in Stockholders' Equity
Share-based compensation	3,439			3,439
Issuance of common stock upon vesting of restricted stock units (in shares)		111,375
Issuance of common stock upon vesting of restricted stock units	0	$ 1		(1)
Issuance of common stock and pre-funded warrants exercise, net of issuance costs	32,908			32,908
Conversion of redeemable convertible preferred stock into common stock (in shares)							0
Extinguishment of private option liability	249			249
Comprehensive loss	(9,704)				(9,705)	1
Balance, end of period (in shares) at Dec. 31, 2021		8,497,025	67,746
Balance, end of period at Dec. 31, 2021	$ 24,395	$ 85	$ (5,056)	$ 580,156	$ (550,452)	$ (338)