Common Stock, Common Stock Warrants and Stock Option Plan - Common Stock Warrants - Tabular Disclosure (Details) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Common Stock Warrants [Member]
Class of Warrant or Right [Line Items]
Warrants to purchase common stock (in shares)	389,423	389,423
Exercise Price (in dollars per share)	$ 7.71	$ 7.71
Common Stock Warrants One [Member]
Class of Warrant or Right [Line Items]
Warrants to purchase common stock (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]
Warrants to purchase common stock (in shares)	315,282	315,282
Exercise Price (in dollars per share)	$ 2.38	$ 2.38