Fair Value Measurements (Valuation Assumptions Used for November 2016 Offering Warrants) (Details) - $ / shares	1 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017		Sep. 30, 2017		Dec. 31, 2016		Sep. 19, 2017	Jun. 30, 2017	Apr. 30, 2017
Common stock closing price					$ 4.40		$ 0.99	$ 0.78
Common Stock Issuance Agreement [Member]
Shares issued per agreements	523,210
Number of shares contingently issuable to Holders per CSIA								523,210
November 2016 Warrants [Member]
Volatility			106.00%		112.00%
Expected term (years)			4 years 1 month 20 days		4 years 10 months 21 days
Risk-free interest rate			1.79%		1.91%
Dividend yield			0.00%		0.00%
Exercise price	$ 0.57	[1]	$ 0.57	[1]	$ 7.50	[1]			$ 1.00
Common stock closing price	$ 0.91		$ 0.91		$ 4.40

[1] In connection with the Company's April 2017 1-for-10 reverse stock split, the exercise price of the warrants was adjusted downward to $1.00 per share. In September 2017, the exercise price of the warrants was further adjusted downward to $0.57 per share in connection with the issuance of 523,210 shares of the Company's common stock to the shareholders who were party to the Common Stock Issuance Agreement. The exercise price of the warrants is subject to further adjustment upon future dilutive issuances of the Company's common stock and stock combination events as defined in the warrant agreements (see Note 6).