Debt (Credit Facilities) (Details) - Revolving credit agreement - USD ($)	1 Months Ended	6 Months Ended
	Mar. 31, 2024	Mar. 31, 2024	Mar. 28, 2024
Credit Agreement 2024 | Line of Credit
Debt Instrument [Line Items]
Debt instrument term	5 years
Maximum borrowing capacity	$ 3,000,000,000	$ 3,000,000,000
Credit facility, amount borrowed and outstanding	$ 0	0
364-Day Agreement | Line of Credit
Debt Instrument [Line Items]
Debt instrument term	364 days
Maximum borrowing capacity	$ 500,000,000	500,000,000
Credit facility, amount borrowed and outstanding	$ 0	0
Credit Agreement 2021 | Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 2,750,000,000
Credit facility, amount borrowed and outstanding			$ 0
Credit facility, early termination fee		$ 0