Annual report pursuant to Section 13 and 15(d)

Income Taxes - Summary of Reconciliation of Expected Statutory Federal Income Tax Provision to Actual Income Tax Provision (Detail)

v3.6.0.2
Income Taxes - Summary of Reconciliation of Expected Statutory Federal Income Tax Provision to Actual Income Tax Provision (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Income Tax Disclosure [Abstract]    
Expected income tax benefit at federal statutory tax rate $ (9,068) $ (5,280)
Change in valuation allowance 9,775 9,815
State income taxes, net of federal benefit (458) (618)
Permanent items 196 (3,542)
Research credits (445) (375)
Income tax (benefit) expense $ 0 $ 0