Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Total
Balances at Dec. 31, 2016	$ 15	$ 236,216	$ (240,610)	$ (4,379)
Balances (in shares) at Dec. 31, 2016	14,977,397
Issuance of stock in connection with financing agreement	$ 9,315	12		12
Return of shares of stock by advisor	(40,000)
Beneficial conversion feature of Advance Notes
Beneficial conversion feature of Convertible Notes
Issuance of stock options for payment of accrued compensation
Stock-based compensation expense		2,115		2,115
Write down in fair value of warrants		(97)		(97)
Issuance of common stock in lieu of cash compensation
Comprehensive loss			(21,987)	(21,987)
Balances at Dec. 31, 2017	$ 15	238,246	(262,597)	(24,336)
Balances (in shares) at Dec. 31, 2017	14,946,712
Conversion of notes payable and related accrued interest and fees to common stock	$ 76	18,356		18,432
Conversion of notes payable and related accrued interest and fees to common stock (in shares)	76,007,754
Issuance of common stock, net of issuance costs	$ 19	2,762		2,781
Issuance of common stock, net of issuance costs (in shares)	18,653,320
Beneficial conversion feature of Advance Notes		271		271
Beneficial conversion feature of Convertible Notes		1,465		1,465
Issuance of stock options for payment of accrued compensation		303		303
Stock-based compensation expense		4,812		4,812
Write down in fair value of warrants
Issuance of common stock in lieu of cash compensation	151,407	85		85
Issuance of common stock in exchange for services	113,333	81		81
Comprehensive loss			(12,004)	(12,004)
Balances at Dec. 31, 2018	$ 110	$ 266,381	$ (274,601)	$ (8,110)
Balances (in shares) at Dec. 31, 2018	109,872,526