Investments - Additional Information (Detail) - USD ($) $ in Billions |
Sep. 30, 2021 |
Jun. 30, 2021 |
|---|---|---|
| Investments Debt And Equity Securities [Abstract] | ||
| Equity investments without readily determinable fair values measured at cost with adjustments for observable changes in price or impairments | $ 3.5 | $ 3.3 |