Utility Regulatory Assets and Liabilities and Regulatory Matters - Regulatory Assets and Liabilities Associated with Utilities (Details) - USD ($)	Sep. 30, 2020	Sep. 30, 2019
Regulatory Assets [Line Items]
Regulatory assets	$ 0	$ 0
UGI Utilities
Regulatory Assets [Line Items]
Regulatory assets	397,000,000	396,000,000
Regulatory Liabilities [Line Items]
Regulatory liabilities	353,000,000	359,000,000
UGI Utilities | Postretirement benefit overcollections
Regulatory Liabilities [Line Items]
Regulatory liabilities	13,000,000	15,000,000
UGI Utilities | Deferred fuel and power refunds
Regulatory Liabilities [Line Items]
Regulatory liabilities	29,000,000	6,000,000
UGI Utilities | State income tax benefits — distribution system repairs
Regulatory Liabilities [Line Items]
Regulatory liabilities	28,000,000	25,000,000
UGI Utilities | PAPUC Temporary Rates Order
Regulatory Liabilities [Line Items]
Regulatory liabilities	7,000,000	31,000,000
UGI Utilities | Excess federal deferred income taxes
Regulatory Liabilities [Line Items]
Regulatory liabilities	274,000,000	280,000,000
UGI Utilities | Other
Regulatory Liabilities [Line Items]
Regulatory liabilities	2,000,000	2,000,000
UGI Utilities | Income taxes recoverable
Regulatory Assets [Line Items]
Regulatory assets	124,000,000	115,000,000
UGI Utilities | Underfunded pension and postretirement plans
Regulatory Assets [Line Items]
Regulatory assets	175,000,000	179,000,000
UGI Utilities | Environmental costs
Regulatory Assets [Line Items]
Regulatory assets	61,000,000	60,000,000
UGI Utilities | Removal costs, net
Regulatory Assets [Line Items]
Regulatory assets	26,000,000	28,000,000
UGI Utilities | Other
Regulatory Assets [Line Items]
Regulatory assets	$ 11,000,000	$ 14,000,000