Goodwill and Intangible Assets - Changes in the Carrying Amount of Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Goodwill
Balance at beginning of period	$ 3,027	$ 3,612
Impairment of goodwill	(195)	(656)	$ 0
Acquisitions		3
Dispositions	(12)
Foreign currency translation	51	68
Balance at end of period	2,871	3,027	3,612
Utilities
Goodwill
Balance at beginning of period	432	432
Impairment of goodwill	0	0
Acquisitions		0
Dispositions	0
Foreign currency translation	0	0
Balance at end of period	432	432	432
Midstream & Marketing
Goodwill
Balance at beginning of period	336	336
Impairment of goodwill	0	0
Acquisitions		0
Dispositions	0
Foreign currency translation	0	0
Balance at end of period	336	336	336
UGI International
Goodwill
Balance at beginning of period	911	840
Impairment of goodwill	0	0
Acquisitions		3
Dispositions	(12)
Foreign currency translation	51	68
Balance at end of period	950	911	840
AmeriGas Propane
Goodwill
Balance at beginning of period	1,348	2,004
Impairment of goodwill	(195)	(656)
Acquisitions		0
Dispositions	0
Foreign currency translation	0	0
Balance at end of period	$ 1,153	$ 1,348	$ 2,004