Fair Value Measurements (Details 3) (USD $)
In Thousands, unless otherwise specified
0 Months Ended 12 Months Ended
Jun. 11, 2014
Dec. 31, 2014
Roll-forward of the fair value of the assets, where fair value is determined by Level 3 inputs    
Issuance of shares of Series A-6 - prepayment   $ 1,220
Conversion of Amount Receivable in Shares of Series A6 Stock to Right to Receive Cash Payment 4,300 (1,220)
Roll-forward of the fair value of the liabilities, where fair value is determined by Level 3 inputs    
Balance at the beginning of the period   7,273
Issuance of shares of Series A-6   (8,889)
Additions - accrued shares of Series A-6   2,717
Additions - warrants   1,511
Change in fair value   505
Warrants liability reclassified to equity   $ (3,117)