Income Taxes (Details 3) (USD $) In Millions	Sep. 30, 2011	Sep. 30, 2010
Deferred tax liabilities (assets)
Excess book basis over tax basis of property, plant and equipment	$ 490.4	$ 414.9
Investment In AmeriGas Partners	172.7	170.9
Intangible assets and goodwill	52.1	51.0
Utility regulatory assets	124.7	127.4
Foreign currency translation adjustment	8.5	12.9
Other	7.2	8.6
Gross deferred tax liabilities	855.6	785.7
Pension plan liabilities	(62.8)	(76.1)
Employee-related benefits	(42.7)	(42.4)
Operating loss carryforwards	(31.8)	(25.5)
Foreign tax credit carryforwards	(60.1)	(61.3)
Utility regulatory liabilities	(12.4)	(13.5)
Derivative financial instruments	(30.5)	(34.8)
Other	(32.9)	(41.7)
Gross deferred tax assets	(273.2)	(295.3)
Deferred tax assets valuation allowance	81.9	78.4
Net deferred tax liabilities	$ 664.3	$ 568.8