Condensed Consolidated Statements of Stockholders’ Equity (Deficit) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning Balance (shares) at Dec. 31, 2018		10,055
Beginning Balance at Dec. 31, 2018	$ 10,137	$ 1	$ 82,898	$ (72,762)
Equity
Stock option exercises (in shares)		42
Stock option exercises	54		54
Stock-based compensation expense	289		289
Issue common stock, net of issuance costs (shares)		748
Issue common stock, net of issuance costs	2,410		2,410
Issue warrants for debt	630		630
Issue stock for debt	202		202
Net loss	(7,852)			(7,852)
Ending Balance (shares) at Mar. 31, 2019		10,845
Ending Balance at Mar. 31, 2019	5,870	$ 1	86,483	(80,614)
Beginning Balance (shares) at Dec. 31, 2018		10,055
Beginning Balance at Dec. 31, 2018	10,137	$ 1	82,898	(72,762)
Equity
Net loss	(21,914)
Ending Balance (shares) at Sep. 30, 2019		10,898
Ending Balance at Sep. 30, 2019	(7,379)	$ 1	87,297	(94,677)
Beginning Balance (shares) at Mar. 31, 2019		10,845
Beginning Balance at Mar. 31, 2019	5,870	$ 1	86,483	(80,614)
Equity
Stock option exercises (in shares)		9
Stock option exercises	11		11
Stock-based compensation expense	336		336
Issue stock for employee stock purchase plan (shares)		44
Issue stock for employee stock purchase plan	103		103
Net loss	(7,665)			(7,665)
Ending Balance (shares) at Jun. 30, 2019		10,898
Ending Balance at Jun. 30, 2019	(1,345)	$ 1	86,933	(88,279)
Equity
Stock-based compensation expense	364		364
Net loss	(6,398)			(6,398)
Ending Balance (shares) at Sep. 30, 2019		10,898
Ending Balance at Sep. 30, 2019	(7,379)	$ 1	87,297	(94,677)
Beginning Balance (shares) at Dec. 31, 2019		34,274
Beginning Balance at Dec. 31, 2019	3,614	$ 3	106,188	(102,577)
Equity
Stock-based compensation expense	328		328
Issue stock for warrant exercises (shares)		3,478
Issue stock for warrant exercises	2,355		2,355
Net loss	(10,510)			(10,510)
Ending Balance (shares) at Mar. 31, 2020		37,752
Ending Balance at Mar. 31, 2020	(4,213)	$ 3	108,871	(113,087)
Beginning Balance (shares) at Dec. 31, 2019		34,274
Beginning Balance at Dec. 31, 2019	$ 3,614	$ 3	106,188	(102,577)
Equity
Stock option exercises (in shares)	0
Net loss	$ (29,376)
Ending Balance (shares) at Sep. 30, 2020		148,348
Ending Balance at Sep. 30, 2020	14,676	$ 15	146,614	(131,953)
Beginning Balance (shares) at Mar. 31, 2020		37,752
Beginning Balance at Mar. 31, 2020	(4,213)	$ 3	108,871	(113,087)
Equity
Stock-based compensation expense	328		328
Issue common stock, net of issuance costs (shares)		16,896
Issue common stock, net of issuance costs	16,366	$ 2	16,364
Issue stock for employee stock purchase plan (shares)		44
Issue stock for employee stock purchase plan	21		21
Issue stock for covenant waiver (shares)		873
Issue stock for covenant waiver	300		300
Issue stock for warrant exercises (shares)		36,410
Issue stock for warrant exercises	1,109	$ 4	1,105
Net loss	(8,074)			(8,074)
Ending Balance (shares) at Jun. 30, 2020		91,975
Ending Balance at Jun. 30, 2020	5,837	$ 9	126,989	(121,161)
Equity
Stock-based compensation expense	447		447
Issue stock for warrant exercises (shares)		50,205
Issue stock for warrant exercises	15,083	$ 5	15,078
Issue stock for acquisition (in shares)		6,168
Issue stock for acquisition	4,101	$ 1	4,100
Net loss	(10,792)			(10,792)
Ending Balance (shares) at Sep. 30, 2020		148,348
Ending Balance at Sep. 30, 2020	$ 14,676	$ 15	$ 146,614	$ (131,953)