Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | |||
---|---|---|---|---|---|
Sep. 30, 2020 |
Sep. 30, 2019 |
Sep. 30, 2020 |
Sep. 30, 2019 |
Dec. 31, 2019 |
|
Income Tax Disclosure [Line Items] | |||||
Deferred tax assets, valuation allowance | $ 53,635 | $ 53,635 | $ 47,809 | ||
Effective tax rate | 0.00% | 0.00% | |||
Change in valuation allowance | $ 5,826 | ||||
Term of ownership change | an ownership change will occur if there is a cumulative change in ownership by 5% shareholders that exceeds 50 percentage points over a rolling three-year period | ||||
ASU No. 2016-09 [Member] | |||||
Income Tax Disclosure [Line Items] | |||||
Excess tax benefits recognized in the provision for income taxes offset by valuation allowance | $ 1,011 | $ 707 | $ 1,759 | $ 2,751 |