Utility Regulatory Assets and Liabilities and Regulatory Matters - Regulatory Assets and Liabilities Associated with Utilities (Details) - USD ($) $ in Millions	Sep. 30, 2019	Sep. 30, 2018
Regulatory Assets [Line Items]
Regulatory assets	$ 3.7	$ 6.3
UGI Utilities
Regulatory Assets [Line Items]
Regulatory assets	395.6	301.0
Regulatory Liabilities [Line Items]
Regulatory liabilities	358.8	390.2
UGI Utilities | Postretirement benefit overcollections
Regulatory Liabilities [Line Items]
Regulatory liabilities	14.5	17.8
UGI Utilities | Deferred fuel and power refunds
Regulatory Liabilities [Line Items]
Regulatory liabilities	6.1	36.7
UGI Utilities | State income tax benefits — distribution system repairs
Regulatory Liabilities [Line Items]
Regulatory liabilities	25.0	22.6
UGI Utilities | PAPUC Temporary Rates Order
Regulatory Liabilities [Line Items]
Regulatory liabilities	31.3	24.4
UGI Utilities | Excess federal deferred income taxes
Regulatory Liabilities [Line Items]
Regulatory liabilities	279.5	285.2
UGI Utilities | Other
Regulatory Liabilities [Line Items]
Regulatory liabilities	2.4	3.5
UGI Utilities | Income taxes recoverable
Regulatory Assets [Line Items]
Regulatory assets	115.2	110.1
UGI Utilities | Underfunded pension and postretirement plans
Regulatory Assets [Line Items]
Regulatory assets	178.6	87.1
UGI Utilities | Environmental costs
Regulatory Assets [Line Items]
Regulatory assets	59.5	58.8
UGI Utilities | Removal costs, net
Regulatory Assets [Line Items]
Regulatory assets	28.3	32.0
UGI Utilities | Other
Regulatory Assets [Line Items]
Regulatory assets	$ 14.0	$ 13.0