CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Preferred Stock [Member]	Common Stock	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	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				(9,119)	(9,119)
Conversion of preferred stock into common stock (in shares)	(4,888)	431,022
Conversion of convertible notes into common stock		$ 4	(4)
Conversion of convertible notes into common stock (in shares)		252,486
Issuance of common stock in connection with purchase agreements		$ 2	616		618
Issuance of common stock in connection with purchase agreements (in shares)		99,457
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
Beneficial conversion feature on issuance of notes			1,604		1,604
Liability recorded related to equity purchase agreement repricing				(460)	(460)
Stock-based compensation			342		342
Balance at end of period at Sep. 30, 2018		$ 16	50,283	(41,121)	9,178
Balance at end of period (in shares) at Sep. 30, 2018	47	1,583,722
Balance at beginning of period at Jun. 30, 2018		$ 15	49,455	(37,272)	12,198
Balance at beginning of period (in shares) at Jun. 30, 2018	47	1,503,969
Increase (Decrease) in Stockholders' Equity
Net loss				(3,849)	(3,849)
Conversion of convertible notes into common stock (in shares)		39,753
Issuance of common stock in connection with purchase agreements		$ 1	(1)
Issuance of common stock in connection with purchase agreements (in shares)		40,000
Issuance of common stock upon exercise of warrants			179		179
Issuance of common stock upon exercise of warrants (in shares)		39,753
Beneficial conversion feature on issuance of notes			528		528
Stock-based compensation			122		122
Balance at end of period at Sep. 30, 2018		$ 16	50,283	(41,121)	9,178
Balance at end of period (in shares) at Sep. 30, 2018	47	1,583,722
Balance at beginning of period at Dec. 31, 2018		$ 23	53,796	(47,696)	6,123
Balance at beginning of period (in shares) at Dec. 31, 2018	47	2,298,738
Increase (Decrease) in Stockholders' Equity
Net loss				(9,462)	(9,462)
Conversion of convertible notes into common stock		$ 24	7,366		7,390
Conversion of convertible notes into common stock (in shares)		2,439,173
Issuance of common stock in connection with purchase agreements		$ 21	5,150		5,171
Issuance of common stock in connection with purchase agreements (in shares)		2,088,077
Write-off debt premiums (net of debt discounts) in conjunction with convertible note conversions			(590)		(590)
Write-off debt derivative liability in conjunction with convertible note conversions			477		477
Proceeds upon issuance of common stock from exercise of warrants		$ 3	1,572		1,575
Proceeds upon issuance of common stock from exercise of warrants (in shares)		310,200
Write-off warrant liability in conjunction with warrant exercises			2,364		2,364
Beneficial conversion feature on issuance of notes			1,792		1,792
Stock-based compensation			455		455
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 Sep. 30, 2019		$ 71	72,381	(57,158)	15,294
Balance at end of period (in shares) at Sep. 30, 2019	47	7,136,117
Balance at beginning of period at Jun. 30, 2019		$ 60	69,428	(55,261)	14,227
Balance at beginning of period (in shares) at Jun. 30, 2019	47	5,993,369
Increase (Decrease) in Stockholders' Equity
Net loss				(1,897)	(1,897)
Conversion of convertible notes into common stock			118		118
Conversion of convertible notes into common stock (in shares)		52,748
Issuance of common stock in connection with purchase agreements		$ 11	2,750		2,761
Issuance of common stock in connection with purchase agreements (in shares)		1,090,000
Write-off debt premiums (net of debt discounts) in conjunction with convertible note conversions			(63)		(63)
Stock-based compensation			148		148
Balance at end of period at Sep. 30, 2019		$ 71	$ 72,381	$ (57,158)	$ 15,294
Balance at end of period (in shares) at Sep. 30, 2019	47	7,136,117