Stockholders' Equity (Deficit) (Details) - USD ($)				1 Months Ended	3 Months Ended	12 Months Ended
	Nov. 22, 2016	Jun. 03, 2016	Mar. 16, 2015	May 31, 2016	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Sale of stock, price per share						$ 0.44
Proceeds from equity offerings, gross	$ 4,000,000	$ 5,000,000
Exercise price of warrants	$ 0.75					$ 2.29	$ 8.19
Proceeds from equity offerings, net						$ 7,566,000	$ 12,384,000
Value of common stock issued						1,545,000
Costs directly allocable to offering						(756,000)	(213,000)
Series March 2015 Warrants [Member]
Class of Stock [Line Items]
Number of securities called by warrants			393,939
Exercise price of warrants			$ 10.75
Private Placement [Member]
Class of Stock [Line Items]
Sale of stock, number of shares sold in transaction			1,575,758
Sale of stock, price per share			$ 8.25
Proceeds from issuance of private placement, gross			$ 13,000,000
Warrant liability			$ 4,200,000
Private Placement [Member] | Placement Agent [Member]
Class of Stock [Line Items]
Number of securities called by warrants			94,545
Exercise price of warrants			$ 10.75
Fees paid to placement agent			$ 800,000
Other expenses related to issuance of warrants					$ 200,000		200,000
Private Placement [Member] | Series March 2015 Warrants [Member]
Class of Stock [Line Items]
Decrease to additional paid-in capital resulting from warrants issued							$ 4,000,000
Securities Purchase Agreement [Member]
Class of Stock [Line Items]
Sale of stock, number of shares sold in transaction				2,127,660
Number of securities called by warrants				1,063,830
Number of shares called by each warrant				0.50
Sale of stock, price per share				$ 2.35
Proceeds from equity offerings, gross				$ 5,000,000
Exercise price of warrants				$ 2.25
Expiration term of warrants (in years)				5 years
Proceeds from equity offerings, net				$ 4,200,000
Placement agent fee as percentage of total gross proceeds of offering				7.00%
Fees paid to placement agent				$ 75,000
Derivative liability				$ 1,800,000
Dividend yield				0.00%
Volatility				123.00%
Risk-free interest rate				1.23%
Value of common stock issued				$ 3,200,000
Costs directly allocable to offering				800,000
Payments of stock issuance costs allocable to warrants				$ 200,000
Changes in estimated fair value						(1,500,000)
Public Offering of Warrants and Common Stock [Member]
Class of Stock [Line Items]
Sale of stock, number of shares sold in transaction	5,335,000
Number of securities called by warrants	5,335,000
Sale of stock, price per share	$ 0.75
Proceeds from equity offerings, gross	$ 4,000,000
Exercise price of warrants	$ 0.75
Expiration term of warrants (in years)	5 years
Proceeds from equity offerings, net	$ 3,700,000
Placement agent fee as percentage of total gross proceeds of offering	6.00%
Fees paid to placement agent	$ 70,000
Derivative liability	2,900,000
Value of common stock issued	1,100,000
Costs directly allocable to offering	700,000
Payments of stock issuance costs allocable to warrants	$ 300,000
Changes in estimated fair value						$ (886,000)