Consolidated Statements of Shareholders' Deficit (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid in Capital [Member]	Accumulated Deficit [Member]
Balance at Dec. 31, 2019	$ (6,712)	$ 233	$ 199,938	$ (206,883)
Balance, Shares at Dec. 31, 2019		23,312,928
Stock-based compensation expense	3,231		3,231
Exercise of stock options, net	(105)		(105)
Exercise of stock options, net, Shares		37,063
Vesting of restricted stock units, net	(916)	$ 1	(917)
Vesting of restricted stock units, net, Shares		105,242
Net income (loss)	(7,692)			(7,692)
Balance at Mar. 31, 2020	(12,194)	$ 234	202,147	(214,575)
Balance, Shares at Mar. 31, 2020		23,455,233
Balance at Dec. 31, 2019	(6,712)	$ 233	199,938	(206,883)
Balance, Shares at Dec. 31, 2019		23,312,928
Net income (loss)	(15,831)
Balance at Sep. 30, 2020	(15,133)	$ 236	207,345	(222,714)
Balance, Shares at Sep. 30, 2020		23,644,631
Balance at Mar. 31, 2020	(12,194)	$ 234	202,147	(214,575)
Balance, Shares at Mar. 31, 2020		23,455,233
Stock-based compensation expense	2,446		2,446
Exercise of stock options, net	379	$ 1	378
Exercise of stock options, net, Shares		105,606
Vesting of restricted stock units, net	(30)	$ 1	(31)
Vesting of restricted stock units, net, Shares		78,067
Net income (loss)	(6,012)			(6,012)
Balance at Jun. 30, 2020	(15,411)	$ 236	204,940	(220,587)
Balance, Shares at Jun. 30, 2020		23,638,906
Stock-based compensation expense	2,409		2,409
Vesting of restricted stock units, net	(4)		(4)
Vesting of restricted stock units, net, Shares		5,725
Net income (loss)	(2,127)			(2,127)
Balance at Sep. 30, 2020	(15,133)	$ 236	207,345	(222,714)
Balance, Shares at Sep. 30, 2020		23,644,631
Balance at Dec. 31, 2020	(14,100)	$ 286	219,998	(234,384)
Balance, Shares at Dec. 31, 2020		28,601,358
Issuance of common stock, net of costs	9,340	$ 22	9,318
Issuance of common stock, net of costs, Shares		2,202,420
Stock-based compensation expense	3,133		3,133
Vesting of restricted stock units, net	(336)	$ 2	(338)
Vesting of restricted stock units, net, Shares		209,541
Net income (loss)	(6,761)			(6,761)
Balance at Mar. 31, 2021	(8,724)	$ 310	232,111	(241,145)
Balance, Shares at Mar. 31, 2021		31,013,319
Balance at Dec. 31, 2020	(14,100)	$ 286	219,998	(234,384)
Balance, Shares at Dec. 31, 2020		28,601,358
Balance at Jun. 30, 2021	26,416	$ 465	265,862	(239,911)
Balance, Shares at Jun. 30, 2021		46,501,849
Balance at Dec. 31, 2020	$ (14,100)	$ 286	219,998	(234,384)
Balance, Shares at Dec. 31, 2020		28,601,358
Exercise of stock options, net, Shares	80
Net income (loss)	$ (9,013)
Balance at Sep. 30, 2021	44,484	$ 466	287,415	(243,397)
Balance, Shares at Sep. 30, 2021		46,614,535
Balance at Mar. 31, 2021	(8,724)	$ 310	232,111	(241,145)
Balance, Shares at Mar. 31, 2021		31,013,319
Issuance of common stock, net of costs	32,103	$ 153	31,950
Issuance of common stock, net of costs, Shares		15,333,332
Stock-based compensation expense	1,929		1,929
Vesting of restricted stock units, net	(126)	$ 2	(128)
Vesting of restricted stock units, net, Shares		155,198
Net income (loss)	1,234			1,234
Balance at Jun. 30, 2021	26,416	$ 465	265,862	(239,911)
Balance, Shares at Jun. 30, 2021		46,501,849
Issuance of common stock, net of costs	20,328		20,328
Stock-based compensation expense	1,319		1,319
Exercise of stock options, net, Shares		80
Vesting of restricted stock units, net	(93)	$ 1	(94)
Vesting of restricted stock units, net, Shares		112,606
Net income (loss)	(3,486)			(3,486)
Balance at Sep. 30, 2021	$ 44,484	$ 466	$ 287,415	$ (243,397)
Balance, Shares at Sep. 30, 2021		46,614,535