Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Fair Value Measurement (Details)

v3.8.0.1
Summary of Significant Accounting Policies - Fair Value Measurement (Details) - Fair Value, Inputs, Level 3
$ in Thousands
3 Months Ended
Mar. 31, 2018
USD ($)
Warrant Liability – Current  
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]  
Balance, beginning of period $ 503
Exercise of warrants (13)
Issuances of warrants 0
Change in fair value - net (27)
Balance, end of period 463
Warrant Liability – Long-Term  
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]  
Balance, beginning of period 0
Exercise of warrants 0
Issuances of warrants 3,092
Change in fair value - net (682)
Balance, end of period 2,410
Warrant Liability – Total  
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]  
Balance, beginning of period 503
Exercise of warrants (13)
Issuances of warrants 3,092
Change in fair value - net (709)
Balance, end of period $ 2,873