Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents (Details) - USD ($) $ in Millions |
Jun. 30, 2023 |
Sep. 30, 2022 |
Jun. 30, 2022 |
Sep. 30, 2021 |
|---|---|---|---|---|
| Restricted Cash and Cash Equivalents Items [Line Items] | ||||
| Cash and cash equivalents | $ 15,590 | $ 15,689 | ||
| Cash, cash equivalents, restricted cash and restricted cash equivalents | 21,039 | 20,377 | $ 18,996 | $ 19,799 |
| U.S. litigation escrow | ||||
| Restricted Cash and Cash Equivalents Items [Line Items] | ||||
| Restricted cash and restricted cash equivalents: | 1,627 | 1,449 | ||
| Customer collateral | ||||
| Restricted Cash and Cash Equivalents Items [Line Items] | ||||
| Restricted cash and restricted cash equivalents: | 2,907 | 2,342 | ||
| Prepaid expenses and other current assets | ||||
| Restricted Cash and Cash Equivalents Items [Line Items] | ||||
| Restricted cash and restricted cash equivalents: | $ 915 | $ 897 |