Condensed Consolidated Statements of Stockholders’ Equity (Unaudited) - USD ($) $ in Thousands	Registered Direct Offering [Member] Common Stock [Member]	Registered Direct Offering [Member] Additional Paid-in Capital [Member]	Registered Direct Offering [Member] Retained Earnings [Member]	Registered Direct Offering [Member]	Direct Offering [Member] Common Stock [Member]	Direct Offering [Member] Additional Paid-in Capital [Member]	Direct Offering [Member] Retained Earnings [Member]	Direct Offering [Member]	At-the-market Offering [Member] Common Stock [Member]	At-the-market Offering [Member] Additional Paid-in Capital [Member]	At-the-market Offering [Member] Retained Earnings [Member]	At-the-market Offering [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
Balances (in shares) at Dec. 31, 2020													16,481,099
Balances at Dec. 31, 2020													$ 2	$ 548,707	$ (500,654)	$ 48,055
Issuance of common stock, net (in shares)					2,875,000				884,695
Issuance of common stock, net					$ 0	$ 20,866	$ 0	$ 20,866	$ 0	$ 7,034	$ 0	$ 7,034				7,000
Stock-based compensation													0	505	0	505
Net loss													$ 0	0	(8,004)	(8,004)
Issuance of common stock upon exercise of options (in shares)													77,858
Issuance of common stock upon exercise of options													$ 0	260	0	260
Balances (in shares) at Mar. 31, 2021													20,318,652
Balances at Mar. 31, 2021													$ 2	577,372	(508,658)	68,716
Balances (in shares) at Dec. 31, 2021													21,039,594
Balances at Dec. 31, 2021													$ 2	582,025	(539,805)	42,222
Issuance of common stock, net (in shares)	3,185,216								54,763
Issuance of common stock, net	$ 0	$ 9,291	$ 0	$ 9,291					$ 0	$ 123	$ 0	$ 123				100
Stock-based compensation													0	620	0	620
Net loss													$ 0	0	(13,057)	$ (13,057)
Issuance of common stock upon exercise of options (in shares)																(0)
Balances (in shares) at Mar. 31, 2022													24,279,573
Balances at Mar. 31, 2022													$ 2	$ 592,059	$ (552,862)	$ 39,199