Leases - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Millions	Sep. 30, 2024	Sep. 30, 2023
Leases [Abstract]
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
Right-of-use assets recorded in Other Assets	$ 876	$ 517
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued expenses	Accrued expenses
Current lease liabilities recorded in Accrued expenses	$ 142	$ 117
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Deferred Income Taxes and Other Liabilities	Deferred Income Taxes and Other Liabilities
Non-current lease liabilities recorded in Deferred Income Taxes and Other Liabilities	$ 667	$ 414