Commitments and Contingencies (Details 1) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012
Contractual obligations under supply, storage and service contracts
2013	$ 712.8
2014	376.8
2015	297.6
2016	104.5
2017	26.5
After 2017	62.7
Gas Utility and Electric Utility supply, storage and transportation contracts [Member]
Contractual obligations under supply, storage and service contracts
2013	173.9
2014	95.0
2015	61.8
2016	43.3
2017	26.5
After 2017	62.7
Midstream & Marketing supply contracts [Member]
Contractual obligations under supply, storage and service contracts
2013	171.1
2014	51.4
2015	4.7
2016	0
2017	0
After 2017	0
AmeriGas Propane supply contracts [Member]
Contractual obligations under supply, storage and service contracts
2013	141.4
2014	87.0
2015	87.7
2016	3.2
2017	0
After 2017	0
International Propane supply contracts [Member]
Contractual obligations under supply, storage and service contracts
2013	226.4
2014	143.4
2015	143.4
2016	58.0
2017	0
After 2017	$ 0

Amount of the recorded unconditional purchase obligation maturing after the fifth fiscal year following the latest fiscal year.

Reference 1: 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

Reference 2: 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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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Amount of the recorded unconditional purchase obligation maturing in the fifth fiscal year following the latest fiscal year.

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Amount of the recorded unconditional purchase obligation maturing in the fourth fiscal year following the latest fiscal year.

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Amount of the recorded unconditional purchase obligation maturing in the second fiscal year following the latest fiscal year.

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Amount of the recorded unconditional purchase obligation maturing in the third fiscal year following the latest fiscal year.

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Amount of the recorded unconditional purchase obligation maturing in the next fiscal year following the latest fiscal year.

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