Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Summary of Changes in Fair Value of Level 3 Financial Liabilities (Details)

v3.3.1.900
Fair Value Measurements - Summary of Changes in Fair Value of Level 3 Financial Liabilities (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
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 (3,552) $ (2,526) $ (6,171)
Ending balance 10,464 31,828  
Warrant Liabilities [Member]      
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Beginning balance 31,828 69,869  
Initial fair value of warrants issued   10,258  
Reclassification of contingent warrant liability to equity upon exercise of warrants (3,552) (2,526)  
Increase (decrease) in estimated fair value of contingent warrant liabilities upon revaluation (17,812) (45,773)  
Ending balance $ 10,464 $ 31,828 $ 69,869