Equity Method Investments (Details) - USD ($) $ in Millions	Mar. 31, 2024	Sep. 30, 2023	Mar. 31, 2023
Schedule of Equity Method Investments [Line Items]
Carrying Value	$ 340	$ 299	$ 219
Midstream & Marketing
Schedule of Equity Method Investments [Line Items]
Carrying Value	305	264	189
Midstream & Marketing | Aurum Renewables
Schedule of Equity Method Investments [Line Items]
Carrying Value	$ 46	$ 45	$ 19
Ownership Interest	40.00%	40.00%	40.00%
Midstream & Marketing | Pine Run
Schedule of Equity Method Investments [Line Items]
Carrying Value	$ 81	$ 77	$ 72
Ownership Interest	49.00%	49.00%	49.00%
Midstream & Marketing | MBL Bioenergy
Schedule of Equity Method Investments [Line Items]
Carrying Value	$ 157	$ 122	$ 78
Ownership Interest	99.99%	99.99%	99.99%
Midstream & Marketing | Other
Schedule of Equity Method Investments [Line Items]
Carrying Value	$ 21	$ 20	$ 20
UGI International
Schedule of Equity Method Investments [Line Items]
Carrying Value	$ 35	$ 35	$ 30