Equity Method Investments - Narrative (Details) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2023 standardCubicFeet MW	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)
Corporate Joint Venture
Schedule of Equity Method Investments [Line Items]
Pre-tax impairment charge		$ 26
Other
Schedule of Equity Method Investments [Line Items]
Pre-tax impairment charge		$ 31	$ 55
Aurum Renewables
Schedule of Equity Method Investments [Line Items]
Landfill gas units | MW	11
Effective ownership interest in AmeriGas OLP (as a percentage)	40.00%
Expected production capacity per day | standardCubicFeet	9,600