Consolidated Statement of Stockholders' Equity and Convertible Preferred Stock (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Series A Convertible Preferred Stock [Member]	Series B Convertible Preferred Stock [Member]	Series C Convertible Preferred Stock [Member]	Total
Balance (in shares) at Dec. 31, 2019	117,329	137
Balance at Dec. 31, 2019	$ 12	$ (685)	$ 224,091	$ (133,701)	$ 48,084	$ 49,814		$ 89,717
Share-based compensation	$ 0	$ 0	(606)	0	0	0		(606)
Restricted stock vesting (in shares)	496	0
Shares repurchased related to share-based compensation (in shares)	(105)	105
Shares repurchased related to share-based compensation	$ 0	$ (322)	0	0	0	0		(322)
Preferred stock dividends	0	0	(10,565)	0				(10,565)
Deemed dividends - accretion of beneficial conversion feature	0	0	(113)	0	113	0		(113)
Net income (loss)	0	0	0	(12,050)	0	0		(12,050)
Restricted stock vesting	$ 0	$ 0	0	0	0	0		0
Preferred stock dividends					5,389	5,135		10,565
Balance (in shares) at Sep. 30, 2020	117,720	242
Balance at Sep. 30, 2020	$ 12	$ (1,007)	212,807	(145,751)	53,586	54,949		66,061
Balance (in shares) at Jun. 30, 2020	117,492	178
Balance at Jun. 30, 2020	$ 12	$ (796)	215,807	(138,573)	51,727	53,192		76,450
Share-based compensation	$ 0	$ 0	629	0	0	0		629
Restricted stock vesting (in shares)	292	0
Shares repurchased related to share-based compensation (in shares)	(64)	64
Shares repurchased related to share-based compensation	$ 0	$ (211)	0	0	0	0		(211)
Preferred stock dividends	0	0	(3,613)	0	1,843	1,757		(3,613)
Deemed dividends - accretion of beneficial conversion feature	0	0	(16)	0	16	0		(16)
Net income (loss)	0	0	0	(7,178)	0	0		(7,178)
Restricted stock vesting	$ 0	$ 0	0	0	0	0		0
Preferred stock dividends								3,613
Balance (in shares) at Sep. 30, 2020	117,720	242
Balance at Sep. 30, 2020	$ 12	$ (1,007)	212,807	(145,751)	53,586	54,949		66,061
Balance (in shares) at Dec. 31, 2020	117,829	249
Balance at Dec. 31, 2020	$ 12	$ (1,031)	209,481	(148,030)	55,522	56,781		60,432
Share-based compensation			(5,799)					(5,799)
Restricted stock vesting (in shares)	590
Shares repurchased related to share-based compensation (in shares)	(95)	95
Shares repurchased related to share-based compensation		$ (279)						(279)
Issuance of common stock, net (in shares)	116
Issuance of common stock, net			151				$ 37,807	151
Stock dividend (in shares)	798
Exercise of common stock warrants (in shares)	1,485
Exercise of common stock warrants			4,365					4,365
Preferred stock dividends			(13,015)		6,045	5,761	1,159	(13,015)
Deemed dividends - accretion of beneficial conversion feature			(47)		47			(47)
Net income (loss)				(14,016)				(14,016)
Issuance of common stock, net (in shares)	116
Issuance of common stock, net			151				37,807	151
Exercise of common stock warrants (in shares)	1,485
Exercise of common stock warrants			4,365					4,365
Preferred stock dividends								13,015
Balance (in shares) at Sep. 30, 2021	120,723	344
Balance at Sep. 30, 2021	$ 12	$ (1,310)	195,136	(162,046)	61,614	62,542	38,966	31,792
Balance (in shares) at Jun. 30, 2021	118,482	300
Balance at Jun. 30, 2021	$ 12	$ (1,171)	199,553	(163,268)	59,509	60,549	33,173	35,126
Share-based compensation			(3,653)					(3,653)
Restricted stock vesting (in shares)	285
Shares repurchased related to share-based compensation (in shares)	(44)	44
Shares repurchased related to share-based compensation		$ (139)						(139)
Issuance of common stock, net (in shares)	116
Issuance of common stock, net			151				4,634	$ 151
Stock dividend (in shares)	399	0
Exercise of common stock warrants (in shares)	1,485							1,500
Exercise of common stock warrants			4,365					$ 4,365
Preferred stock dividends			(5,264)		2,089	1,993	1,159	(5,264)
Deemed dividends - accretion of beneficial conversion feature			(16)		16			(16)
Net income (loss)				1,222				1,222
Issuance of common stock, net (in shares)	116
Issuance of common stock, net			151				4,634	$ 151
Exercise of common stock warrants (in shares)	1,485							1,500
Exercise of common stock warrants			4,365					$ 4,365
Preferred stock dividends								5,264
Balance (in shares) at Sep. 30, 2021	120,723	344
Balance at Sep. 30, 2021	$ 12	$ (1,310)	$ 195,136	$ (162,046)	$ 61,614	$ 62,542	$ 38,966	$ 31,792