Utility Regulatory Assets and Liabilities and Regulatory Matters - Regulatory Assets and Liabilities Associated with Utilities (Details) - UGI Utilities - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Regulatory Assets [Line Items]
Regulatory assets	$ 368.9	$ 395.1
Regulatory Liabilities [Line Items]
Regulatory liabilities	49.2	55.6
Postretirement benefit overcollections
Regulatory Liabilities [Line Items]
Regulatory liabilities	17.5	17.5
Deferred fuel and power refunds
Regulatory Liabilities [Line Items]
Regulatory liabilities	10.6	22.3
State income tax benefits — distribution system repairs
Regulatory Liabilities [Line Items]
Regulatory liabilities	18.4	15.1
Other
Regulatory Liabilities [Line Items]
Regulatory liabilities	2.7	0.7
Income taxes recoverable
Regulatory Assets [Line Items]
Regulatory assets	121.4	115.7
Underfunded pension and postretirement plans
Regulatory Assets [Line Items]
Regulatory assets	141.3	183.1
Environmental costs
Regulatory Assets [Line Items]
Regulatory assets	61.6	59.4
Deferred fuel and power costs
Regulatory Assets [Line Items]
Regulatory assets	7.7	0.2
Removal costs, net
Regulatory Assets [Line Items]
Regulatory assets	31.0	27.9
Other
Regulatory Assets [Line Items]
Regulatory assets	$ 5.9	$ 8.8