CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Preferred Stock [Member]	Common Stock	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Common Stock	Total
Balance at beginning of period at Dec. 31, 2017		$ 7	$ 44,560	$ (31,542)		$ 13,025
Balance at beginning of period (in shares) at Dec. 31, 2017	4,935	679,774
Increase (Decrease) in Stockholders' Equity
Net loss				(15,694)		(15,694)
Conversion of preferred stock into common stock		$ 4	(4)
Conversion of preferred stock into common stock (in shares)	(4,888)	431,022
Conversion of convertible notes into common stock		$ 4	2,352			2,356
Conversion of convertible notes into common stock (in shares)		384,896			252,486
Issuance of common stock in connection with purchase agreements		$ 5	2,003			2,008
Issuance of common stock in connection with purchase agreements (in shares)		428,050
Issuance of common stock in exchange for cancelation of other current liabilities		$ 1	1,896			1,897
Issuance of common stock in exchange for cancelation of other current liabilities (in shares)		120,983
Issuance of common stock upon exercise of warrants		$ 2	1,269			1,271
Issuance of common stock upon exercise of warrants (in shares)		252,486
Issuance of common stock for consulting services in connection with the merger			39			39
Issuance of common stock for consulting services in connection with the merger (in shares)		1,527
Warrant modification recorded as debt discount in conjunction with convertible note issuance			11			11
Beneficial conversion feature on issuance of notes			2,118			2,118
Write-off beneficial conversion feature in conjunction with convertible note extinguishment			(1,029)			(1,029)
Write-off debt discounts (net of debt premiums) in conjunction with convertible note conversions			(210)			(210)
Write-off debt derivative liability in conjunction with convertible note conversions			301			301
Liability recorded related to equity purchase agreement repricing				(460)		(460)
Non-cash stock-based compensation			490			490
Balance at end of period at Dec. 31, 2018		$ 23	53,796	(47,696)		6,123
Balance at end of period (in shares) at Dec. 31, 2018	47	2,298,738
Increase (Decrease) in Stockholders' Equity
Net loss				(13,243)		(13,243)
Conversion of convertible notes into common stock		$ 25	7,528			7,553
Conversion of convertible notes into common stock (in shares)		2,511,173			310,200
Issuance of common stock in connection with purchase agreements		$ 28	6,600			6,628
Issuance of common stock in connection with purchase agreements (in shares)		2,778,077
Proceeds upon issuance of common stock from exercise of warrants		$ 3	1,572			1,575
Write-off warrant liability in conjunction with warrant exercises			2,364			2,364
Issuance of common stock upon exercise of warrants (in shares)		310,200
Beneficial conversion feature on issuance of notes			1,792			1,792
Write-off debt discounts (net of debt premiums) in conjunction with convertible note conversions			(731)			(731)
Write-off debt derivative liability in conjunction with convertible note conversions			477			477
Non-cash stock-based compensation			668			668
Payment of fractional common shares in conjunction with reverse stock split			(1)			(1)
Payment of fractional common shares in conjunction with reverse stock split (in shares)		(71)
Balance at end of period at Dec. 31, 2019		$ 79	$ 74,065	$ (60,939)		$ 13,205
Balance at end of period (in shares) at Dec. 31, 2019	47	7,898,117