Income Taxes - Summary of Reconciliation of the Gross Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Income Tax Disclosure [Abstract] | |||
| Unrecognized tax benefit beginning of year | $ 31,702 | $ 27,812 | $ 18,793 |
| Increases in current year tax positions | 43,855 | 6,301 | 8,437 |
| Increases in prior year tax positions | 0 | 114 | 582 |
| Decreases in prior year tax positions | 0 | (1,829) | 0 |
| Decreases in prior year tax positions due to settlements | 0 | (696) | 0 |
| Decreases in prior year tax positions due to lapse of statute of limitations | 0 | 0 | 0 |
| Unrecognized tax benefit end of year | $ 75,557 | $ 31,702 | $ 27,812 |