Income Taxes (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Income Taxes
Foreign tax credits			$ 63.0	$ 12.1	$ 34.9
Undistributed earnings of foreign subsidiaries			50.8
Deferred tax assets relating to operating loss carryforwards			32.5	27.9
Valuation allowance provided for deferred tax assets related to state net operating loss carryforwards and other state deferred tax assets of certain subsidiaries			15.6
Increase (decrease) in valuation allowance			(72.1)
Unrecognized income tax benefits			3.2	2.4	3.4	$ 2.9
Accrued interest included in unrecognized income tax benefits			0.1
Unrecognized tax benefits if recognized would impact the reported effective tax rate			3.2
Foreign Tax Credits
Income Taxes
Increase (decrease) in valuation allowance			66.0
Foreign Operating Loss Carryforwards
Income Taxes
Increase (decrease) in valuation allowance			8.0
State Operating Loss Benefits
Income Taxes
Increase (decrease) in valuation allowance			(1.9)
Accrued Interest Included
Income Taxes
Unrecognized income tax benefits			3.2
Foreign Country
Income Taxes
Foreign tax credit carryforwards			113.7
State and Local Jurisdiction
Income Taxes
Decrease in income tax expense due to state tax flow through of accelerated depreciation			1.5	2.0	$ 1.5
Operating loss carryforwards			158.5
Deferred tax assets and associated valuation allowance for unrealized state tax benefits for equity compensation deductions			6.5	$ 6.7
UGI International Holdings
Income Taxes
Deferred tax assets relating to operating loss carryforwards			0.6
AmeriGas Propane
Income Taxes
Operating loss carryforwards			12.1
Deferred tax assets relating to operating loss carryforwards			4.7
Other Subsidiaries
Income Taxes
Deferred tax assets relating to operating loss carryforwards			8.7
UGI International
Income Taxes
Valuation allowance operating loss carryforwards related to acquisition			11.0
Flaga
Income Taxes
Deferred tax assets relating to operating loss carryforwards			13.0
Flaga | Foreign Country
Income Taxes
Operating loss carryforwards			59.4
UGI France
Income Taxes
Deferred tax assets relating to operating loss carryforwards			8.0
UGI France | Foreign Country
Income Taxes
Operating loss carryforwards			$ 23.4
France | Foreign Country
Income Taxes
Income tax expense		$ 5.7
France | UGI France
Income Taxes
Income tax expense	$ 5.7