Legal Matters - Schedule of Accrued Litigation for Both Covered and Non-Covered Litigation (Detail) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | |
|---|---|---|---|
Jun. 30, 2022 |
Jun. 30, 2022 |
Jun. 30, 2021 |
|
| Loss Contingency Accrual [Roll Forward] | |||
| Balance at beginning of period | $ 983 | $ 914 | |
| Balance at end of period | $ 1,486 | 1,486 | 900 |
| Uncovered Litigation | |||
| Loss Contingency Accrual [Roll Forward] | |||
| Provision for legal matters | 2 | 5 | |
| Covered Litigation | |||
| Loss Contingency Accrual [Roll Forward] | |||
| Provision for legal matters | 878 | 23 | |
| Payments for legal matters | (377) | (42) | |
| U.S. Covered Litigation | |||
| Loss Contingency Accrual [Roll Forward] | |||
| Balance at beginning of period | 881 | 888 | |
| Provision for legal matters | 716 | 861 | 0 |
| Payments for legal matters | (262) | (7) | |
| Balance at end of period | 1,480 | 1,480 | 881 |
| VE Territory Covered Litigation | |||
| Loss Contingency Accrual [Roll Forward] | |||
| Balance at beginning of period | 102 | 21 | |
| Provision for legal matters | 17 | 23 | |
| Payments for legal matters | (114) | (29) | |
| Balance at end of period | $ 5 | $ 5 | $ 15 |