Balance Sheet Components - Summary of Changes in the Asset Retirement Obligations (Detail) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Mar. 31, 2021 |
Mar. 31, 2020 |
|
| Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
| Balance, beginning of year | $ 1,078 | |
| Accretion expense | 87 | $ 41 |
| Liabilities incurred | 1,037 | |
| Balance, end of year | $ 1,165 | $ 1,078 |