Commitments and Contingencies (Details 1) (USD $) In Millions	Sep. 30, 2011
Contractual obligations under supply, storage and service contracts
2012	$ 524.6
2013	157.4
2014	79.8
2015	47.8
2016	25.0
After 2016	64.0
Gas Utility and Electric Utility supply, storage and transportation contracts [Member]
Contractual obligations under supply, storage and service contracts
2012	213.0
2013	103.3
2014	76.2
2015	47.8
2016	25.0
After 2016	64.0
Midstream & Marketing supply contracts [Member]
Contractual obligations under supply, storage and service contracts
2012	222.5
2013	54.1
2014	3.6
2015	0
2016	0
After 2016	0
AmeriGas Propane Supply Contracts [Member]
Contractual obligations under supply, storage and service contracts
2012	65.8
2013	0
2014	0
2015	0
2016	0
After 2016	0
International Propane Supply Contracts [Member]
Contractual obligations under supply, storage and service contracts
2012	23.3
2013	0
2014	0
2015	0
2016	0
After 2016	$ 0

The aggregate remaining amount of payments due after the fifth year after the balance sheet date to extinguish a recorded unconditional purchase obligation.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 47

-Paragraph 10

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 440

-SubTopic 10

-Section 50

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=6394976&loc=d3e25383-109308

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