Condensed Consolidated Statements of Stockholders' Equity (Deficit) (Unaudited) - USD ($) $ in Thousands	Common Stock [Member] At Market Issuance Sales Agreement [Member]	Common Stock [Member]	Preferred Stock [Member] At Market Issuance Sales Agreement [Member]	Preferred Stock [Member] Series A Preferred Stock [Member]	Preferred Stock [Member]	Additional Paid-in Capital [Member] At Market Issuance Sales Agreement [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member] At Market Issuance Sales Agreement [Member]	Retained Earnings [Member]	At Market Issuance Sales Agreement [Member]	Total
Balance (in shares) at Dec. 31, 2020		36,902,361			7,531
Balance at Dec. 31, 2020		$ 368			$ 1		$ 513,744		$ (539,414)		$ (25,301)
Stock-based compensation expense (in shares)		72,229			0
Stock-based compensation expense		$ 1			$ 0		147		0		148
Issuance of shares pursuant to direct offerings (in shares)	1,368,362		0
Issuance of shares pursuant to direct offerings		13			$ 0	$ 14,853		$ 0		$ 14,866
Net loss and comprehensive loss		0							(5,944)		(5,944)
Reclassification of warrant liability		$ 0					3,179		0		3,179
Balance (in shares) at Mar. 31, 2021		38,342,952			7,531
Balance at Mar. 31, 2021		$ 382			$ 1		531,923		(545,358)		(13,052)
Balance (in shares) at Dec. 31, 2021		43,656,169		2,300	329
Balance at Dec. 31, 2021		$ 435		$ 1	$ 1		613,572		(573,400)		40,609
Stock-based compensation expense (in shares)		236,995		0	0
Stock-based compensation expense		$ 2		$ 0	$ 0		431		0		433
Issuance of shares pursuant to direct offerings (in shares)		6,857,140		0	0
Issuance of shares pursuant to direct offerings		$ 69		$ 0	$ 0		11,672		0		11,741
Dividends paid and declared		0		0	0		0		(1,265)		(1,265)
Net loss and comprehensive loss		$ 0		$ 0	$ 0		0		(5,912)		(5,912)
Balance (in shares) at Mar. 31, 2022		50,750,304		2,300	329
Balance at Mar. 31, 2022		$ 506		$ 1	$ 1		$ 625,675		$ (580,577)		$ 45,606