Income Taxes (Details 3) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Sep. 30, 2011
Deferred tax liabilities (assets)
Excess book basis over tax basis of property, plant and equipment	$ 582.0	$ 490.4
Investment In AmeriGas Partners	293.2	172.7
Intangible assets and goodwill	61.2	52.1
Utility regulatory assets	140.4	124.7
Foreign currency translation adjustment	3.6	8.5
Other	6.8	7.2
Gross deferred tax liabilities	1,087.2	855.6
Pension plan liabilities	(72.7)	(62.8)
Employee-related benefits	(43.0)	(42.7)
Operating loss carryforwards	(38.0)	(31.8)
Foreign tax credit carryforwards	(55.5)	(60.1)
Utility regulatory liabilities	(11.8)	(12.4)
Derivative financial instruments	(37.7)	(30.5)
Other	(31.9)	(32.9)
Gross deferred tax assets	(290.6)	(273.2)
Deferred tax assets valuation allowance	81.6	81.9
Net deferred tax liabilities	$ 878.2	$ 664.3