Income Taxes (Details 3) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Deferred tax liabilities (assets)
Excess book basis over tax basis of property, plant and equipment	$ 626.9	$ 582.0
Investment In AmeriGas Partners	313.0	292.8
Intangible assets and goodwill	65.1	61.2
Utility regulatory assets	101.6	140.4
Foreign currency translation adjustment	9.5	3.6
Other	2.7	4.1
Gross deferred tax liabilities	1,118.8	1,084.1
Pension plan liabilities	(36.2)	(72.7)
Employee-related benefits	(47.9)	(43.0)
Operating loss carryforwards	(32.1)	(33.4)
Foreign tax credit carryforwards	(81.8)	(55.5)
Utility regulatory liabilities	(15.5)	(11.8)
Derivative financial instruments	(15.0)	(37.7)
Other	(20.5)	(31.1)
Gross deferred tax assets	(249.0)	(285.2)
Deferred tax assets valuation allowance	97.6	77.0
Net deferred tax liabilities	$ 967.4	$ 875.9