Fair Value Measurements - Changes in Lender Warrants and Stock Option Awards Liability (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Lender Warrants    
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance as of January 1 $ 1,614 $ 0
Issuance of liabilities 0 943
Change in fair value (482) 671
Reclassification of liabilities to equity (1,132) 0
Balance as of December 31 0 1,614
Stock Option Liability Awards    
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance as of January 1 461 0
Issuance of liabilities 0 410
Change in fair value (173) 51
Reclassification of liabilities to equity (288) 0
Balance as of December 31 $ 0 $ 461