Stock Compensation Plans - Weighted Average Assumptions for Options Granted (Details) - Stock Options	9 Months Ended
	Jun. 30, 2023 $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	33.00%
Expected term (in years)	5 years
Expected dividend yield (percent)	2.99%
Risk free interest rate (percent)	3.58%
Grant date fair value (in dollars per share)	$ 8.65