Debt and Financing Arrangements - Short-Term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2023	Sep. 30, 2022
Short-Term Debt [Line Items]
Short-term debt	$ 1,737	$ 669
Weighted average interest rate on short-term debt outstanding	2.90%	0.50%
Notes Payable to Banks
Short-Term Debt [Line Items]
Short-term debt	$ 20	$ 10
Commercial Paper
Short-Term Debt [Line Items]
Short-term debt	1,554	172
Loans Payable
Short-Term Debt [Line Items]
Short-term debt	$ 163	$ 487

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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Name:	us-gaap_ShortTermBorrowings
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant