Common and Preferred Stock (Details) - $ / shares	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Equity [Abstract]
Common stock, capital shares reserved for future issuance (in shares)	8,800,000
Treasury stock, shares, acquired (in shares)	21,300,000	5,700,000
Treasury shares re-issued (in shares)	1,800,000	1,300,000
Preferred stock, shares authorized (in shares)	5,400,000	5,400,000
Preferred stock, par or stated (in dollars per share)	$ 2.50	$ 2.50
Preferred stock, shares issued (in shares)	0	0