Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	November 2019 Offering [Member] Preferred Stock [Member] Series A Preferred Stock [Member]	November 2019 Offering [Member] Preferred Stock [Member] Series B Preferred Stock [Member]	November 2019 Offering [Member] Preferred Stock [Member] Series C Preferred Stock [Member]	November 2019 Offering [Member] Common Stock [Member]	November 2019 Offering [Member] Additional Paid-in Capital [Member]	November 2019 Offering [Member] Retained Earnings [Member]	November 2019 Offering [Member]	Purchase Agreement with LPC [Member] Preferred Stock [Member] Series A Preferred Stock [Member]	Purchase Agreement with LPC [Member] Preferred Stock [Member] Series B Preferred Stock [Member]	Purchase Agreement with LPC [Member] Preferred Stock [Member] Series C Preferred Stock [Member]	Purchase Agreement with LPC [Member] Common Stock [Member]	Purchase Agreement with LPC [Member] Additional Paid-in Capital [Member]	Purchase Agreement with LPC [Member] Retained Earnings [Member]	Purchase Agreement with LPC [Member]	January 2021 Offering [Member] Preferred Stock [Member] Series A Preferred Stock [Member]	January 2021 Offering [Member] Preferred Stock [Member] Series B Preferred Stock [Member]	January 2021 Offering [Member] Preferred Stock [Member] Series C Preferred Stock [Member]	January 2021 Offering [Member] Common Stock [Member]	January 2021 Offering [Member] Additional Paid-in Capital [Member]	January 2021 Offering [Member] Retained Earnings [Member]	January 2021 Offering [Member]	Conversion of Series A Convertible Preferred Stock into Common Stock [Member] Preferred Stock [Member] Series A Preferred Stock [Member]	Conversion of Series A Convertible Preferred Stock into Common Stock [Member] Preferred Stock [Member] Series B Preferred Stock [Member]	Conversion of Series A Convertible Preferred Stock into Common Stock [Member] Preferred Stock [Member] Series C Preferred Stock [Member]	Conversion of Series A Convertible Preferred Stock into Common Stock [Member] Common Stock [Member]	Conversion of Series A Convertible Preferred Stock into Common Stock [Member] Additional Paid-in Capital [Member]	Conversion of Series A Convertible Preferred Stock into Common Stock [Member] Retained Earnings [Member]	Conversion of Series A Convertible Preferred Stock into Common Stock [Member]	Conversion of Series C Convertible Preferred Stock Into Common Stock [Member] Preferred Stock [Member] Series A Preferred Stock [Member]	Conversion of Series C Convertible Preferred Stock Into Common Stock [Member] Preferred Stock [Member] Series B Preferred Stock [Member]	Conversion of Series C Convertible Preferred Stock Into Common Stock [Member] Preferred Stock [Member] Series C Preferred Stock [Member]	Conversion of Series C Convertible Preferred Stock Into Common Stock [Member] Common Stock [Member]	Conversion of Series C Convertible Preferred Stock Into Common Stock [Member] Additional Paid-in Capital [Member]	Conversion of Series C Convertible Preferred Stock Into Common Stock [Member] Retained Earnings [Member]	Conversion of Series C Convertible Preferred Stock Into Common Stock [Member]	Series A and Series B Warrants [Member] Preferred Stock [Member] Series A Preferred Stock [Member]	Series A and Series B Warrants [Member] Preferred Stock [Member] Series B Preferred Stock [Member]	Series A and Series B Warrants [Member] Preferred Stock [Member] Series C Preferred Stock [Member]	Series A and Series B Warrants [Member] Common Stock [Member]	Series A and Series B Warrants [Member] Additional Paid-in Capital [Member]	Series A and Series B Warrants [Member] Retained Earnings [Member]	Series A and Series B Warrants [Member]	Series A-2 and Series B-2 Warrants [Member] Preferred Stock [Member] Series A Preferred Stock [Member]	Series A-2 and Series B-2 Warrants [Member] Preferred Stock [Member] Series B Preferred Stock [Member]	Series A-2 and Series B-2 Warrants [Member] Preferred Stock [Member] Series C Preferred Stock [Member]	Series A-2 and Series B-2 Warrants [Member] Common Stock [Member]	Series A-2 and Series B-2 Warrants [Member] Additional Paid-in Capital [Member]	Series A-2 and Series B-2 Warrants [Member] Retained Earnings [Member]	Series A-2 and Series B-2 Warrants [Member]	Preferred Stock [Member] Series A Preferred Stock [Member]	Preferred Stock [Member] Series B Preferred Stock [Member]	Preferred Stock [Member] Series C Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Series B Preferred Stock [Member]	Total
Balances (in shares) at Dec. 31, 2019																																																		185,218	31,678	0	707,571
Balances at Dec. 31, 2019																																																		$ 0	$ 0	$ 0	$ 0	$ 214,432	$ (197,911)		$ 16,521
Issuance costs	$ 0	$ 0	$ 0	$ 0	$ (33)	$ 0	$ (33)	$ 0	$ 0	$ 0	$ 0	$ (494)	$ 0	$ (494)
Conversion of convertible preferred stock into common stock (in shares)																						(185,218)	0	0	185,218
Conversion of convertible preferred stock into common stock																						$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0
Issuance of common shares in connection with common warrant exercises																																				$ 0	$ 0	$ 0	$ 0	$ 7,814	$ 0	$ 7,814	$ 0	$ 0	$ 0	$ 0	$ 593	$ 0	$ 593
Issuance of common shares in connection with common warrant exercises (in shares)																																							1,115,863							93,129											1,209,000
Modification of Series A and B warrants in connection with 2020 Warrant Offering																																																		0	0	0	0	1,838	0		$ 1,838
Issuance of Series A-2 and B-2 warrants in connection with 2020 Warrant Offering																																																		0	0	0	0	1,838	0		1,838
Issuance costs for Series A-2 and B-2 warrants in connection with 2020 Warrant Offering																																																		0	0	0	0	(1,838)	0		(1,838)
Issuance costs for Series A-2 and B-2 warrants in connection with 2020 Warrant Offering																																																		(0)	(0)	(0)	(0)	1,838	(0)		1,838
Transaction costs in connection with 2020 Warrant Offering																																																		0	0	0	0	(334)	0		(334)
Transaction costs in connection with 2020 Warrant Offering																																																		(0)	(0)	(0)	(0)	334	(0)		334
Issuance of stock (in shares)								0	0	0	52,500
Issuance of stock								$ 0	$ 0	$ 0	$ 0	341	0	341
Series B convertible preferred stock dividends																																																		$ 0	$ 0	$ 0	$ 0	(4,149)	0		(4,149)
Series B convertible preferred stock dividends paid in PIK shares (in shares)																																																		0	4,141	0	0			4,141
Series B convertible preferred stock dividends paid in PIK shares																																																		$ 0	$ 0	$ 0	$ 0	4,141	0		4,141
Stock-based compensation expense																																																		$ 0	$ 0	$ 0	$ 0	2,577	0		2,577
Issuance of common shares from employee stock purchase plan (in shares)																																																		0	0	0	84
Issuance of common shares from employee stock purchase plan																																																		$ 0	$ 0	$ 0	$ 0	0	0		0
Issuance of common shares for vesting of restricted stock award granted to consultant (in shares)																																																		0	0	0	25
Issuance of common shares for vesting of restricted stock award granted to consultant																																																		$ 0	$ 0	$ 0	$ 0	0	0		0
Issuance of restricted common shares in connection with consulting agreement (in shares)																																																		0	0	0	10,995
Issuance of restricted common shares in connection with consulting agreement																																																		$ 0	$ 0	$ 0	$ 0	74	0		74
Reverse stock split - rounding adjustment (in shares)																																																		0	0	0	5,931
Reverse stock split - rounding adjustment																																																		$ 0	$ 0	$ 0	$ 0	0	0		0
Net loss																																																		$ 0	$ 0	$ 0	$ 0	0	(21,915)		(21,915)
Balances (in shares) at Dec. 31, 2020																																																		0	35,819	0	2,171,316
Balances at Dec. 31, 2020																																																		$ 0	$ 0	$ 0	$ 0	226,800	(219,826)		6,974	[1]
Issuance costs								$ 0	$ 0	$ 0	$ 0	(70)	0	(70)
Conversion of convertible preferred stock into common stock (in shares)																													0	0	(2,450,880)	2,450,880
Conversion of convertible preferred stock into common stock																													$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0
Issuance of common shares in connection with common warrant exercises																																																		$ 0	$ 0	$ 0	$ 0	179	0		$ 179
Issuance of common shares in connection with common warrant exercises (in shares)																																																		0	0	0	52,760				52,760
Modification of Series A and B warrants in connection with 2020 Warrant Offering																																																		$ 0	$ 0	$ 0	$ 0	373	0		$ 373
Issuance of stock (in shares)								0	0	0	250,000				0	0	2,450,880	5,666,760
Issuance of stock								$ 0	$ 0	$ 0	$ 0	$ 704	$ 0	$ 704	$ 0	$ 0	$ 0	$ 1	$ 25,121	$ 0	$ 25,122
Series B convertible preferred stock dividends																																																		$ 0	$ 0	$ 0	$ 0	(4,691)	0		(4,691)
Series B convertible preferred stock dividends paid in PIK shares (in shares)																																																		0	4,685	0	0			4,685
Series B convertible preferred stock dividends paid in PIK shares																																																		$ 0	$ 0	$ 0	$ 0	4,685	0		4,685
Stock-based compensation expense																																																		$ 0	$ 0	$ 0	$ 0	3,779	0		3,779
Issuance of common shares from employee stock purchase plan (in shares)																																																		0	0	0	28,130
Issuance of common shares from employee stock purchase plan																																																		$ 0	$ 0	$ 0	$ 0	38	0		$ 38
Issuance of restricted common shares in connection with consulting agreement (in shares)																																																									0
Net loss																																																		$ 0	$ 0	$ 0	$ 0	0	(22,027)		$ (22,027)
Balances (in shares) at Dec. 31, 2021																																																		0	40,504	0	10,619,846
Balances at Dec. 31, 2021																																																		$ 0	$ 0	$ 0	$ 1	$ 256,918	$ (241,853)		$ 15,066

[1] The condensed consolidated balance sheet as of December 31, 2020 has been derived from the audited consolidated financial statements as of that date.