Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Reconciliation of Warrant Liability Measured at Fair Value (Detail)

v3.7.0.1
Stockholders' Equity - Reconciliation of Warrant Liability Measured at Fair Value (Detail) - USD ($)
$ in Thousands
6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]    
Change in fair value of common stock warrants $ (249) $ 626
Level 3 Inputs    
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]    
Beginning Balance 1,743  
Change in fair value of common stock warrants (249)  
Ending Balance $ 1,494