SCHEDULE I — CONDENSED FINANCIAL INFORMATION OF REGISTRANT (PARENT COMPANY) - BALANCE SHEETS (Details) - USD ($) $ in Millions	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Current assets
Cash and cash equivalents	$ 241	$ 405	$ 855
Prepaid expenses and other current assets	114	120
Total current assets	2,045	3,802
Other assets	988	755
Total assets	15,401	17,575	$ 16,723
Current liabilities
Current maturities of long-term debt	57	149
Total current liabilities	2,274	2,444
Long-term debt	6,543	6,483
Other noncurrent liabilities	1,235	1,219
Total liabilities	11,007	11,501
Commitments and contingencies (Note 1)
Equity:
Preferred Stock, without par value (authorized - 5,000,000; issued - 220,000 and 220,000, respectively)	167	162
Common Stock, without par value (authorized – 450,000,000 shares; issued – 210,906,052 and 210,560,494 shares, respectively)	1,503	1,483
Retained earnings	3,027	4,841
Accumulated other comprehensive loss	(256)	(380)
Treasury stock, at cost	(55)	(40)
Total UGI Corporation stockholders’ equity	4,386	6,066
Total liabilities and equity	$ 15,401	$ 17,575
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)	220,000	220,000	220,000	0
Common Stock, shares authorized (in shares)	450,000,000	450,000,000
Common Stock, shares issued (in shares)	210,906,052	210,560,494
Parent Company
Current assets
Cash and cash equivalents	$ 7	$ 20
Accounts receivable – related parties	11	24
Prepaid expenses and other current assets	23	20
Total current assets	41	64
Property, plant and equipment, net	0	1
Investments in subsidiaries	5,343	7,035
Other assets	143	97
Total assets	5,527	7,197
Current liabilities
Current maturities of long-term debt	38	125
Accounts and notes payable	28	20
Accrued liabilities	39	51
Total current liabilities	105	196
Long-term debt	969	889
Other noncurrent liabilities	67	46
Total liabilities	1,141	1,131
Commitments and contingencies (Note 1)
Equity:
Preferred Stock, without par value (authorized - 5,000,000; issued - 220,000 and 220,000, respectively)	167	162
Common Stock, without par value (authorized – 450,000,000 shares; issued – 210,906,052 and 210,560,494 shares, respectively)	1,503	1,483
Retained earnings	3,027	4,841
Accumulated other comprehensive loss	(256)	(380)
Treasury stock, at cost	(55)	(40)
Total UGI Corporation stockholders’ equity	4,386	6,066
Total liabilities and equity	$ 5,527	$ 7,197
Condensed Financial Information of Registrant [Abstract]
Common Stock, shares authorized (in shares)	450,000,000	450,000,000
Common Stock, shares issued (in shares)	210,906,052	210,560,494