Redeemable Convertible Preferred Stock (Details) - USD ($)							1 Months Ended	3 Months Ended		6 Months Ended	12 Months Ended
	Jan. 12, 2018	Sep. 19, 2017	Jun. 27, 2017	Apr. 08, 2016	Apr. 07, 2016	Jun. 13, 2013	Sep. 30, 2017	Apr. 08, 2016	Apr. 07, 2016	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Jun. 29, 2017
Class of Stock [Line Items]
Accretion to redemption value of Series B redeemable convertible preferred stock									$ 1,858,000			$ (1,493,000)
Shares of common stock issued upon conversion of preferred stock				150,556
Proceeds from equity offerings, net											$ 9,353,000	7,566,000
Derivative liability											292,000	2,443,000
Liability fair value adjustment											(2,010,000)
Dividends payable											$ 38,000	$ 38,000
Common stock closing price		$ 0.99									$ 1.01	$ 4.40
Charge for common stock issuance											$ 519,000
Warrant issuance expense												$ 569,000
Charges related to Second Issuance included as component of general and administrative expense											519,000
Value of common stock issued											519,000	$ 1,545,000
Fair value of shares issued											22,000
Common Stock Issuance Agreement [Member]
Class of Stock [Line Items]
Future shares of common stock approved to be issued per agreement												28,684
Capital raised limit for Price Protection Obligation											10,000,000
Shares issued per agreement				85,346			523,210
Number of securities called by warrants				31,519				31,519
Common Stock Issuance Agreement Amendment [Member]
Class of Stock [Line Items]
Future shares of common stock approved to be issued per agreement			28,684
Derivative liability													$ 22,000
Change in fair value of derivative liabilities											104,000
Shares issued per agreement										28,684
Fair value of shares issued										$ 22,000
CSIA Second Issuance [Member]
Class of Stock [Line Items]
Number of shares contingently issuable to Holders per CSIA		523,210
Value of common stock issued		$ 519,000
Price Protection Obligation [Member]
Class of Stock [Line Items]
Shares issued per agreement												75,020
Dilutive Financing Derivative Liability [Member]
Class of Stock [Line Items]
Derivative liability												$ 126,000
Liability fair value adjustment											(104,000)	(611,000)
Fair value of shares issued											$ 22,000
June 2016 Offering Warrants [Member]
Class of Stock [Line Items]
Liability fair value adjustment												$ 1,500,000
Subsequent Event [Member]
Class of Stock [Line Items]
Proceeds from equity offerings, net	$ 3,500,000
Sale of stock, price per share	$ 1.00
Series B Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized						9,357,935
Preferred Stock, initial stated value per share						$ 1.40
Preferred Stock, par value per share						$ 0.01
Preferred Stock dividend rate						10.00%
Number of shares converted				7,527,853
Change in fair value of derivative liabilities								$ (1,500,000)
Series B Convertible Preferred Stock [Member] | Common Stock Issuance Agreement [Member]
Class of Stock [Line Items]
Exercise price of warrants				$ 40.50	$ 70.00			$ 40.50	$ 70.00
Warrant expiration date					June 26, 2018						March 31, 2021
Fofeited cash payments in respect of accrued dividends				$ 2,200,000