SCHEDULE I — CONDENSED FINANCIAL INFORMATION OF REGISTRANT (PARENT COMPANY) - BALANCE SHEETS (Details) - USD ($) $ in Millions	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Current assets
Cash and cash equivalents	$ 213	$ 241	$ 405
Prepaid expenses and other current assets	69	127
Total current assets	1,651	2,045
Other assets	1,112	988
Total assets	15,098	15,401	$ 17,575
Current liabilities
Current maturities of long-term debt	235	57
Derivative instruments	28	60
Total current liabilities	2,060	2,274
Long-term debt	6,443	6,543
Other noncurrent liabilities	1,202	1,235
Total liabilities	10,744	11,007
Commitments and contingencies (Note 1)
Equity:
Preferred Stock, without par value (authorized - 5,000,000; issued - 0 and 220,000, respectively)	0	167
Common Stock, without par value (authorized – 450,000,000 shares; issued – 216,124,332 and 210,906,052 shares, respectively)	1,676	1,503
Retained earnings	2,978	3,027
Accumulated other comprehensive loss	(253)	(256)
Treasury stock, at cost	(56)	(55)
Total UGI Corporation stockholders’ equity	4,345	4,386
Total liabilities and equity	$ 15,098	$ 15,401
Condensed Financial Information of Registrant [Abstract]
UGI Preferred Stock, without par value, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	220,000	220,000	220,000
Common stock, shares authorized (in shares)	450,000,000	450,000,000
Common stock, shares issued (in shares)	216,124,332	210,906,052
Parent Company
Current assets
Cash and cash equivalents	$ 4	$ 7
Accounts receivable – related parties	23	11
Prepaid expenses and other current assets	2	23
Total current assets	29	41
Investments in subsidiaries	5,625	5,343
Other assets	145	143
Total assets	5,799	5,527
Current liabilities
Current maturities of long-term debt	0	38
Accounts and notes payable	15	28
Derivative instruments	1	0
Accrued liabilities	58	39
Total current liabilities	74	105
Long-term debt	1,312	969
Other noncurrent liabilities	68	67
Total liabilities	1,454	1,141
Commitments and contingencies (Note 1)
Equity:
Preferred Stock, without par value (authorized - 5,000,000; issued - 0 and 220,000, respectively)	0	167
Common Stock, without par value (authorized – 450,000,000 shares; issued – 216,124,332 and 210,906,052 shares, respectively)	1,676	1,503
Retained earnings	2,978	3,027
Accumulated other comprehensive loss	(253)	(256)
Treasury stock, at cost	(56)	(55)
Total UGI Corporation stockholders’ equity	4,345	4,386
Total liabilities and equity	$ 5,799	$ 5,527
Condensed Financial Information of Registrant [Abstract]
Common stock, shares authorized (in shares)	450,000,000	450,000,000
Common stock, shares issued (in shares)	216,124,332	210,906,052