Leases - Supplemental Balance Sheet Information, Leases (Details) - USD ($) $ in Millions |
Dec. 31, 2023 |
Sep. 30, 2023 |
---|---|---|
Leases [Abstract] | ||
Operating lease right-of-use assets | $ 1,389 | $ 1,389 |
Operating lease liabilities - current | 327 | 318 |
Operating lease liabilities - noncurrent | $ 1,079 | $ 1,086 |