Goodwill and Intangible Assets - Changes in the Carrying Amount of Goodwill (Details) - USD ($)	3 Months Ended		12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Goodwill
Balance at beginning of period			$ 3,612,000,000	$ 3,770,000,000
Purchase accounting adjustments				(5,000,000)
Foreign currency translation			68,000,000	(153,000,000)
Impairment of goodwill			(656,000,000)	0	$ 0
Acquisitions			3,000,000
Balance at end of period	$ 3,027,000,000		3,027,000,000	3,612,000,000	3,770,000,000
AmeriGas Propane
Goodwill
Balance at beginning of period			2,004,000,000	2,004,000,000
Purchase accounting adjustments				0
Foreign currency translation			0	0
Impairment of goodwill	(656,000,000)	$ (656,000,000)	(656,000,000)
Acquisitions			0
Balance at end of period	1,348,000,000		1,348,000,000	2,004,000,000	2,004,000,000
UGI International
Goodwill
Balance at beginning of period			840,000,000	993,000,000
Purchase accounting adjustments				0
Foreign currency translation			68,000,000	(153,000,000)
Impairment of goodwill			0
Acquisitions			3,000,000
Balance at end of period	911,000,000		911,000,000	840,000,000	993,000,000
Midstream & Marketing
Goodwill
Balance at beginning of period			336,000,000	336,000,000
Purchase accounting adjustments				0
Foreign currency translation			0	0
Impairment of goodwill			0
Acquisitions			0
Balance at end of period	336,000,000		336,000,000	336,000,000	336,000,000
Utilities
Goodwill
Balance at beginning of period			432,000,000	437,000,000
Purchase accounting adjustments				(5,000,000)
Foreign currency translation			0	0
Impairment of goodwill			0
Acquisitions			0
Balance at end of period	$ 432,000,000		$ 432,000,000	$ 432,000,000	$ 437,000,000