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Income Taxes - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
Income Tax Disclosure [Line Items]          
Deferred tax assets, valuation allowance $ 47,577   $ 47,577   $ 42,349
Effective tax rate     0.00% 0.00%  
Change in valuation allowance     $ 5,228    
ASU No. 2016-09 [Member]          
Income Tax Disclosure [Line Items]          
Excess tax benefits recognized in the provision for income taxes offset by valuation allowance $ 2,236 $ 186 $ 2,044 $ 711