Debt - Schedule of Long-term Debt Instruments (Footnotes) (Details) - USD ($)	12 Months Ended
Sep. 30, 2025	Sep. 30, 2024
UGI International
Debt Instrument [Line Items]
Fixed rate (as a percentage)	3.10%	3.10%
Senior Notes \| UGI Utilities, Inc.
Debt Instrument [Line Items]
Principal amount	$ 175,000,000
Line of Credit \| UGI Corporation
Debt Instrument [Line Items]
Effective interest rate (as a percentage)	6.64%	7.45%
Mountaineer senior notes \| Senior Notes \| UGI Utilities, Inc.
Debt Instrument [Line Items]
Principal amount	$ 250,000,000	$ 180,000,000
Unamortized premium	$ 14,000,000	$ 16,000,000
Mountaineer senior notes \| Senior Notes \| UGI Utilities, Inc. \| Minimum
Debt Instrument [Line Items]
Interest rate (as a percentage)	3.50%
Mountaineer senior notes \| Senior Notes \| UGI Utilities, Inc. \| Maximum
Debt Instrument [Line Items]
Interest rate (as a percentage)	6.21%
Variable-rate term loan \| Term Loan \| UGI Utilities, Inc.
Debt Instrument [Line Items]
Effective interest rate (as a percentage)	3.92%	3.92%
Fixed rate (as a percentage)	2.82%
Quarterly installments	$ 2,000,000
Variable-rate term loan \| Term Loan \| Midstream & Marketing
Debt Instrument [Line Items]
Effective interest rate (as a percentage)	7.39%	7.09%
Quarterly installments	$ 2,000,000
Variable-rate term loan \| Term Loan Due March 2028 \| UGI International
Debt Instrument [Line Items]
Effective interest rate (as a percentage)	4.94%	4.95%
Due September 2026 \| Midstream & Marketing
Debt Instrument [Line Items]
Fixed rate (as a percentage)	4.53%
Due September 2028 \| Midstream & Marketing
Debt Instrument [Line Items]
Fixed rate (as a percentage)	3.55%
Other
Debt Instrument [Line Items]
Effective interest rate (as a percentage)	9.13%
3-year Term loan \| Term Loan \| UGI Corporation
Debt Instrument [Line Items]
Effective interest rate (as a percentage)		6.09%
5-year Term Loan \| Term Loan \| UGI Corporation
Debt Instrument [Line Items]
Effective interest rate (as a percentage)		6.75%
Due October \| UGI Corporation
Debt Instrument [Line Items]
Fixed rate (as a percentage)	3.61%
Due October \| Term Loan \| UGI Corporation
Debt Instrument [Line Items]
Effective interest rate (as a percentage)	6.09%

Face (par) amount of debt instrument at time of issuance.

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of the required periodic payments applied to principal.

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Fixed interest rate that will be received or paid upon exercise of the interest rate swaption contract.

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