Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements, Warrant Liabilities, Changes in Level 3, and Outstanding Debt (Details)

v3.2.0.727
Fair Value Measurements, Warrant Liabilities, Changes in Level 3, and Outstanding Debt (Details) - USD ($)
$ in Thousands
 6 Months Ended 12 Months Ended
Jun. 30, 2015
Jun. 30, 2014
Dec. 31, 2014
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Reclassification of contingent warrant liability to equity upon exercise of warrants $ (3,088) $ (2,526)  
Warrant Liabilities [Member]      
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Beginning balance 31,828    
Reclassification of contingent warrant liability to equity upon exercise of warrants (3,088)    
Net increase in estimated fair value of contingent warrant liabilities upon revaluation 216    
Ending balance $ 28,956   $ 31,828
Warrant Liabilities [Member] | Minimum [Member]      
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]      
Expected volatility (in hundredths) 69.80%   69.60%
Risk-free interest rate (in hundredths) 0.29%   0.03%
Expected term 1 year 5 months 8 days   1 month 2 days
Warrant Liabilities [Member] | Maximum [Member]      
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]      
Expected volatility (in hundredths) 70.90%   72.90%
Risk-free interest rate (in hundredths) 0.69%   0.67%
Expected term 1 year 8 months 8 days   2 years 2 months 8 days
Carrying Value [Member]      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Interest bearing obligations $ 48,004   $ 35,308
Fair Value [Member]      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Interest bearing obligations $ 49,686   $ 36,461