Equity Method Investments (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2024	Mar. 31, 2025	Mar. 31, 2024
Schedule of Equity Method Investments [Line Items]
Carrying Value	$ 370	$ 393	$ 340
Other
Schedule of Equity Method Investments [Line Items]
Carrying Value	1	1	0
Midstream & Marketing
Schedule of Equity Method Investments [Line Items]
Carrying Value	359	382	305
Midstream & Marketing \| Aurum Renewables
Schedule of Equity Method Investments [Line Items]
Carrying Value	$ 47	$ 47	$ 46
Ownership Interest	40.00%	40.00%	40.00%
Midstream & Marketing \| Pine Run
Schedule of Equity Method Investments [Line Items]
Carrying Value	$ 86	$ 91	$ 81
Ownership Interest	49.00%	49.00%	49.00%
Midstream & Marketing \| MBL Bioenergy
Schedule of Equity Method Investments [Line Items]
Carrying Value	$ 206	$ 221	$ 157
Ownership Interest	99.99%	99.99%	99.99%
Midstream & Marketing \| Other
Schedule of Equity Method Investments [Line Items]
Carrying Value	$ 20	$ 23	$ 21
UGI International
Schedule of Equity Method Investments [Line Items]
Carrying Value	10	$ 10	$ 35
UGI International \| Joint Venture
Schedule of Equity Method Investments [Line Items]
Loss on extinguishments of debt	$ 26

Amount of other-than-temporary decline in value that has been recognized against investment accounted for under equity method of accounting.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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