Other Financial Data - Other Assets (Details) - USD ($) $ in Millions	Sep. 30, 2023	Sep. 30, 2022
Other Assets [Line Items]
Operating lease right-of-use assets	$ 550	$ 439
Unbilled receivables (contract assets)	$ 559	$ 428
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Assets, Noncurrent, Other than Noncurrent Investments and Property, Plant and Equipment	Assets, Noncurrent, Other than Noncurrent Investments and Property, Plant and Equipment
Other Assets
Other Assets [Line Items]
Pension assets	$ 995	$ 868
Deferred income taxes	100	85
Asbestos-related insurance receivables	$ 53	$ 68