Warrants - Summary of Warrants Issued and Outstanding (Details) - $ / shares	Dec. 31, 2019	Dec. 31, 2018	Aug. 15, 2016	Jun. 30, 2015
Class of Warrant or Right [Line Items]
Warrants Outstanding (in shares)	274,524	274,524
Trinity - September 2018
Class of Warrant or Right [Line Items]
Exercise Price (in USD per share)	$ 3.59
Warrants Outstanding (in shares)	75,000	75,000
Amendment to Hercules Term Loan - June 2015
Class of Warrant or Right [Line Items]
Exercise Price (in USD per share)	$ 147.4
Warrants Outstanding (in shares)	2,035	2,035
Hercules Term Loan - June 2014
Class of Warrant or Right [Line Items]
Exercise Price (in USD per share)	$ 176.8			$ 147.4
Warrants Outstanding (in shares)	1,583	1,583
Private Investment in Public Equity (PIPE)
Class of Warrant or Right [Line Items]
Warrants Outstanding (in shares)	195,906		480,000
Private Investment in Public Equity (PIPE) | PIPE Financing - Series B - August 2016
Class of Warrant or Right [Line Items]
Exercise Price (in USD per share)	$ 31
Warrants Outstanding (in shares)	195,906	195,906