Utility Regulatory Assets and Liabilities and Regulatory Matters - Regulatory Assets and Liabilities Associated with Gas Utility and Electric Utility (Details) - UGI Utilities - USD ($) $ in Millions	Jun. 30, 2017	Sep. 30, 2016	Jun. 30, 2016
Regulatory Assets
Regulatory assets	$ 398.8	$ 395.1	$ 345.3
Regulatory Liabilities
Regulatory liabilities	48.7	55.6	69.9
Postretirement benefits
Regulatory Liabilities
Regulatory liabilities	16.7	17.5	19.7
Deferred fuel and power refunds
Regulatory Liabilities
Regulatory liabilities	12.6	22.3	34.4
State tax benefits — distribution system repairs
Regulatory Liabilities
Regulatory liabilities	16.7	15.1	14.6
Other
Regulatory Liabilities
Regulatory liabilities	2.7	0.7	1.2
Income taxes recoverable
Regulatory Assets
Regulatory assets	122.7	115.7	119.6
Underfunded pension and postretirement plans
Regulatory Assets
Regulatory assets	171.8	183.1	133.4
Environmental costs
Regulatory Assets
Regulatory assets	61.6	59.4	60.7
Deferred fuel and power costs
Regulatory Assets
Regulatory assets	7.0	0.1	0.0
Removal costs, net
Regulatory Assets
Regulatory assets	29.4	27.9	22.4
Other
Regulatory Assets
Regulatory assets	$ 6.3	$ 8.9	$ 9.2