Goodwill and Intangible Assets (Details 1) (USD $) In Millions, unless otherwise specified	12 Months Ended									12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 AmeriGas Propane [Member]	Sep. 30, 2011 AmeriGas Propane [Member]	Sep. 30, 2012 Gas Utility [Member]	Sep. 30, 2011 Gas Utility [Member]	Sep. 30, 2012 Energy Services [Member]	Sep. 30, 2011 Energy Services [Member]	Sep. 30, 2010 Energy Services [Member]	Sep. 30, 2012 Antargaz [Member]	Sep. 30, 2011 Antargaz [Member]	Sep. 30, 2012 Flaga & Other [Member]	Sep. 30, 2011 Flaga & Other [Member]	Sep. 30, 2012 Corporate & Other [Member]		Sep. 30, 2011 Corporate & Other [Member]		Sep. 30, 2010 Corporate & Other [Member]
Changes in the carrying amount of goodwill
Goodwill, Beginning Balance	$ 1,562.2	$ 1,562.7	$ 696.3	$ 683.1	$ 182.1	$ 180.1	$ 2.8	$ 2.8	$ 2.8	$ 591.8	$ 602.7	$ 82.2	$ 87.0	$ 7.0	[1]	$ 7.0	[1]	$ 7.0	[1]
Goodwill acquired	1,283.2	13.1	1,223.1	13.1						46.4		13.7
Purchase accounting adjustments	(0.2)	(1.1)	(0.2)	0.1		2.0							(3.2)
Foreign currency translation	(26.9)	(12.5)								(26.2)	(10.9)	(0.7)	(1.6)
Goodwill, Ending Balance	$ 2,818.3	$ 1,562.2	$ 1,919.2	$ 696.3	$ 182.1	$ 182.1	$ 2.8	$ 2.8	$ 2.8	$ 612.0	$ 591.8	$ 95.2	$ 82.2	$ 7.0	[1]	$ 7.0	[1]	$ 7.0	[1]

[1] Corporate & Other results principally comprise Electric Utility, UGI Enterprises’ heating, ventilation, air-conditioning, refrigeration and electrical contracting businesses (“HVAC/R”), net expenses of UGI’s captive general liability insurance company, and UGI Corporation’s unallocated corporate and general expenses and interest income. Corporate & Other assets principally comprise cash, short-term investments, the assets of Electric Utility and HVAC/R, and an intercompany loan. The intercompany loan and associated interest is removed in the segment presentation.