Pension Plans - Percentage of Total Plan Assets (Details) - Pension Plan	Sep. 30, 2025	Sep. 30, 2024
Defined Benefit Plan Disclosure [Line Items]
Asset Category	100.00%	100.00%
Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Asset Category	19.00%	12.00%
Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Asset Category	57.00%	62.00%
Commodity Option
Defined Benefit Plan Disclosure [Line Items]
Asset Category	6.00%	6.00%
Insurance Company
Defined Benefit Plan Disclosure [Line Items]
Asset Category	8.00%	9.00%
Cash
Defined Benefit Plan Disclosure [Line Items]
Asset Category	10.00%	11.00%