Capitalization and Short-Term Borrowings - Schedule of Share-Based Compensation for Restricted Stock Units and Performance Shares (Details) - $ / shares	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Non-Performance Based Restricted Stock Units (RSUs)
Number of Restricted Stock Units
Outstanding, beginning of year (in shares)	347,427
Granted (in shares)	133,173	128,950	172,513
Vested (in shares)	(119,147)
Forfeited (in shares)	(19,267)
Outstanding, end of year (in shares)	342,186	347,427
Weighted Average Fair Value per Award
Outstanding, beginning of year (in dollars per share)	$ 44.58
Granted (in dollars per share)	58.10	$ 54.10	$ 37.98
Vested (in dollars per share)	44.82
Forfeited (in dollars per share)	46.88
Outstanding, end of year (in dollars per share)	$ 49.63	$ 44.58
Performance Shares
Number of Restricted Stock Units
Outstanding, beginning of year (in shares)	607,179
Granted (in shares)	202,259	195,397	309,470
Vested (in shares)	(278,687)
Forfeited (in shares)	(22,805)
Change in Units Based on Performance Achieved (in shares)	78,845
Outstanding, end of year (in shares)	586,791	607,179
Weighted Average Fair Value per Award
Outstanding, beginning of year (in dollars per share)	$ 48.60
Granted (in dollars per share)	64.28	$ 65.39	$ 39.19
Vested (in dollars per share)	42.58
Forfeited (in dollars per share)	57.20
Change in Units Based on Performance Achieved (in dollars per share)	40.69
Outstanding, end of year (in dollars per share)	$ 55.46	$ 48.60