Goodwill and Intangible Assets - Changes in the Carrying Amount of Goodwill (Details) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2015	Sep. 30, 2014
Goodwill
Goodwill - balance at beginning of period		$ 2,833.4	$ 2,873.7
Acquisitions		200.0	9.6
Dispositions		(1.0)
Purchase accounting adjustments			(1.8)
Foreign currency translation		(79.0)	(48.1)
Goodwill - balance at beginning of period		2,953.4	2,833.4
Operating Segments | AmeriGas Propane
Goodwill
Goodwill - balance at beginning of period		1,945.1	1,941.0
Acquisitions		10.9	6.8
Dispositions		0.0
Purchase accounting adjustments			(2.7)
Foreign currency translation		0.0	0.0
Goodwill - balance at beginning of period		1,956.0	1,945.1
Operating Segments | Gas Utility
Goodwill
Goodwill - balance at beginning of period		182.1	182.1
Acquisitions		0.0	0.0
Dispositions		0.0
Purchase accounting adjustments			0.0
Foreign currency translation		0.0	0.0
Goodwill - balance at beginning of period		182.1	182.1
Operating Segments | Energy Services
Goodwill
Goodwill - balance at beginning of period		5.6	2.8
Acquisitions		0.0	2.8
Dispositions		0.0
Purchase accounting adjustments			0.0
Foreign currency translation		0.0	0.0
Goodwill - balance at beginning of period		5.6	5.6
Operating Segments | UGI France
Goodwill
Goodwill - balance at beginning of period		601.2	643.7
Acquisitions		186.2	0.0
Dispositions		0.0
Purchase accounting adjustments			0.0
Foreign currency translation		(66.0)	(42.5)
Goodwill - balance at beginning of period		721.4	601.2
Operating Segments | Flaga & Other
Goodwill
Goodwill - balance at beginning of period		92.4	97.1
Acquisitions		2.9
Dispositions		0.0
Purchase accounting adjustments			0.9
Foreign currency translation		(13.0)	(5.6)
Goodwill - balance at beginning of period		82.3	92.4
Corporate & Other
Goodwill
Goodwill - balance at beginning of period	[1]	7.0	7.0
Acquisitions		0.0	0.0
Dispositions		(1.0)
Purchase accounting adjustments			0.0
Foreign currency translation		0.0	0.0
Goodwill - balance at beginning of period	[1]	$ 6.0	$ 7.0

[1] Corporate & Other results principally comprise (1) Electric Utility, (2) Enterprises’ heating, ventilation, air-conditioning, refrigeration and electrical contracting businesses (“HVAC”), (3) net expenses of UGI’s captive general liability insurance company, and (4) UGI Corporation’s unallocated corporate and general expenses and interest income. In addition, Corporate & Other results also include the effects of net pre-tax gains and (losses) on commodity derivative instruments not associated with current-period transactions totaling $(119.1), $(18.0) and $7.4 in Fiscal 2015, Fiscal 2014 and Fiscal 2013, respectively. Corporate & Other assets principally comprise cash, short-term investments, the assets of Electric Utility and HVAC. Through March 2014, Corporate & Other also had an intercompany loan. The intercompany loan interest is removed in the segment presentation.