Balance Sheet Components - Summary of Other Noncurrent Liabilities (Detail) - USD ($) $ in Thousands |
Mar. 31, 2021 |
Mar. 31, 2020 |
|---|---|---|
| Other Liabilities, Noncurrent [Abstract] | ||
| Asset retirement obligations, noncurrent | $ 1,165 | $ 1,078 |
| Liabilities for early exercise of common stock options by related party | 43,821 | |
| Total other liabilities, noncurrent | $ 1,165 | $ 44,899 |