Credit Facilities, Short-term Borrowings and Long-term Debt (Narrative) (Details) - USD ($)		3 Months Ended
	Nov. 15, 2023	Dec. 31, 2023	Sep. 30, 2023
Debt Instrument [Line Items]
Outstanding borrowings			$ 0
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 1,000,000,000
Line of credit facility, maximum borrowing capacity extension		1,500,000,000
Principal amount borrowing outstanding		$ 65,100,000
Effective interest rate		0.0646
Minimum [Member] | SOFR [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Basis spread on variable rate		0.875%
Maximum [Member] | SOFR [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Basis spread on variable rate		1.75%
Series H and K Notes [Member]
Debt Instrument [Line Items]
Payment of principal balance	$ 75,000,000