Common Stock, Common Stock Warrants and Stock Option Plan - Common Stock Warrants - Tabular Disclosure (Details) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Common Stock Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Shares (in shares)	389,423	411,514
Exercise Price (in dollars per share)	$ 7.71	$ 7.60
Common Stock Warrants One [Member]
Class of Warrant or Right [Line Items]
Number of Shares (in shares)	74,141	74,141
Exercise Price (in dollars per share)	$ 30.35	$ 30.35
Common Stock Warrants Two [Member]
Class of Warrant or Right [Line Items]
Number of Shares (in shares)		7,378
Exercise Price (in dollars per share)		$ 12.20
Common Stock Warrants Three [Member]
Class of Warrant or Right [Line Items]
Number of Shares (in shares)	315,282	329,995
Exercise Price (in dollars per share)	$ 2.38	$ 2.38