Shareholder's Equity (Details) $ / shares in Units, $ in Thousands						12 Months Ended
	Nov. 06, 2019 USD ($) $ / shares shares	Oct. 25, 2019 USD ($) $ / shares shares	Mar. 12, 2019 USD ($) $ / shares shares	Jul. 03, 2018 USD ($) $ / shares shares	Nov. 27, 2017 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	May 30, 2019 $ / shares shares	Dec. 31, 2018 shares
Class of Stock Disclosures [Abstract]
Exercise price of warrants (in dollars per share) | $ / shares	$ 0.9942	$ 1.41
Preferred stock, shares outstanding (in shares)						0		0
Issuance of common stock, net (in shares)	1,219,076	575,830
Public offering price (in dollars per share) | $ / shares	$ 1.12	$ 1.15
Warrants to purchase shares of common stock (in shares)	1,219,076	575,830
Gross proceeds from public stock offering | $	$ 1,360	$ 660
Warrant expiry period	5 years	5 years
Warrants exercisable period		6 months
Expected Stock Price Volatility [Member]
Class of Stock Disclosures [Abstract]
Warrants measurement input						1.3621
July 2018 Offering [Member]
Class of Stock Disclosures [Abstract]
Issuance of common stock, net (in shares)				181,941
Public offering price (in dollars per share) | $ / shares				$ 29.68
Gross proceeds from public stock offering | $				$ 5,400
Net proceeds from public stock offering | $				$ 4,600
Number of shares issuable on the exercise of warrants (in shares)				554,322
March 2019 Offering [Member]
Class of Stock Disclosures [Abstract]
Issuance of common stock, net (in shares)			455,178
Public offering price (in dollars per share) | $ / shares			$ 5.25
Warrants [Member]
Class of Stock Disclosures [Abstract]
Number of warrants vested (in shares)						0
Warrants [Member] | Minimum [Member]
Class of Stock Disclosures [Abstract]
Exercise price of warrants (in dollars per share) | $ / shares						$ 0.99
Warrants [Member] | Maximum [Member]
Class of Stock Disclosures [Abstract]
Exercise price of warrants (in dollars per share) | $ / shares						43,848
Warrants [Member] | Consultant [Member]
Class of Stock Disclosures [Abstract]
Exercise price of warrants (in dollars per share) | $ / shares						$ 1.93	$ 3.18
Warrants to purchase shares of common stock (in shares)							100,000
Series F Convertible Preferred Stock [Member]
Class of Stock Disclosures [Abstract]
Gross proceeds from issuance of convertible preferred stock | $					$ 18,000
Net proceeds from issuance of convertible preferred stock | $					$ 16,200
Conversion price (in dollars per share) | $ / shares	$ 0.9942	$ 1.41	$ 5.25	$ 29.68	$ 63.00
Number of consecutive trading days considered for expiration						20 days
Number of consecutive trading days						30 days
Preferred stock, shares issued (in shares)					18,000	535		535
Number of shares issuable on conversion of preferred stock (in shares)					286,714
Preferred stock, shares outstanding (in shares)						535		535
Aggregate cash placement fee	8.00%	8.00%	8.00%	8.00%
Series F Convertible Preferred Stock [Member] | Minimum [Member]
Class of Stock Disclosures [Abstract]
Percentage of volume weighted average price of common stock					300.00%
Trading volume for each trading day | $					$ 200
Series F Convertible Preferred Stock [Member] | Warrants [Member]
Class of Stock Disclosures [Abstract]
Warrants to purchase shares of common stock (in shares)					573,310
Warrants issued to the placement agent (in shares)						0
Series F Convertible Preferred Stock [Member] | Warrant Series 1 [Member]
Class of Stock Disclosures [Abstract]
Exercise price of warrants (in dollars per share) | $ / shares				$ 29.68	$ 63.00
Warrants to purchase shares of common stock (in shares)					16
Series F Convertible Preferred Stock [Member] | Warrant Series 2 [Member]
Class of Stock Disclosures [Abstract]
Exercise price of warrants (in dollars per share) | $ / shares				$ 29.68	$ 63.00
Warrants to purchase shares of common stock (in shares)					16
Series G Convertible Preferred Stock [Member]
Class of Stock Disclosures [Abstract]
Gross proceeds from issuance of convertible preferred stock | $			$ 12,400
Net proceeds from issuance of convertible preferred stock | $			$ 11,000
Conversion price (in dollars per share) | $ / shares			$ 5.25
Number of consecutive trading days						30 days
Preferred stock, shares outstanding (in shares)						0
Beneficial conversion amount | $						$ 4,500
Conversion of preferred stock into common stock (in shares)						1,910,536
Beneficial ownership limitation			4.99%
Series G Convertible Preferred Stock [Member] | March 2019 Offering [Member]
Class of Stock Disclosures [Abstract]
Number of shares issuable on conversion of preferred stock (in shares)			1,910,536
Series G Convertible Preferred Stock [Member] | Warrant Series 1 [Member]
Class of Stock Disclosures [Abstract]
Exercise price of warrants (in dollars per share) | $ / shares			$ 5.25
Number of shares issuable on the exercise of warrants (in shares)			2,365,714
Series G Convertible Preferred Stock [Member] | Warrant Series 2 [Member]
Class of Stock Disclosures [Abstract]
Exercise price of warrants (in dollars per share) | $ / shares			$ 5.25
Number of shares issuable on the exercise of warrants (in shares)			2,365,714