Other Financial Information (Intangibles) (Details) - USD ($) $ in Millions	Mar. 31, 2023	Sep. 30, 2022
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 9,800	$ 9,671
Less: Accumulated amortization	3,501	3,099
Net carrying amount	6,299	6,572
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Net carrying amount	3,329	3,436
Intellectual Property
Finite-Lived Intangible Assets [Line Items]
Net carrying amount	$ 2,770	$ 2,934