Balance Sheet Components - Schedule of Property And Equipment, Net (Detail) - USD ($) $ in Thousands |
Mar. 31, 2021 |
Mar. 31, 2020 |
|---|---|---|
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, gross | $ 111,212 | $ 112,165 |
| Less: accumulated depreciation and amortization | (50,328) | (34,283) |
| Property and equipment, net | 60,884 | 77,882 |
| Computer And Software [Member] | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, gross | 13,252 | 13,364 |
| Laboratory Equipment And Software [Member] | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, gross | 48,636 | 49,367 |
| Furniture And Office Equipment [Member] | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, gross | 8,803 | 8,868 |
| Leasehold Improvements [Member] | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, gross | 39,668 | 39,713 |
| Capitalized Asset Retirement Obligations [Member] | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, gross | $ 853 | $ 853 |