PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS Part 10 (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013
Pension Plans [Member] \| Paid From Qualified Trust [Member]
Expected benefit payments [Abstract]
2014	$ 22.9
2015	25.3
2016	27.2
2017	30.8
2018	34.2
2019 - 2023	227.2
Pension Plans [Member] \| Paid From Laclede Gas Funds [Member]
Expected benefit payments [Abstract]
2014	0.4
2015	0.5
2016	0.5
2017	0.6
2018	0.6
2019 - 2023	4.5
Postretirement Plans [Member] \| Paid From Qualified Trust [Member]
Expected benefit payments [Abstract]
2014	9.5
2015	9.9
2016	10.7
2017	11.7
2018	12.8
2019 - 2023	84.1
Postretirement Plans [Member] \| Paid From Laclede Gas Funds [Member]
Expected benefit payments [Abstract]
2014	0.3
2015	0.3
2016	0.3
2017	0.4
2018	0.4
2019 - 2023	$ 2.2

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Amount of benefits expected to be paid in the five fiscal years after the fifth fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

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- Definition

Amount of benefits expected to be paid in the next fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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Amount of benefits expected to be paid in the fifth fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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Amount of benefits expected to be paid in the fourth fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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Amount of benefits expected to be paid in the third fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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Amount of benefits expected to be paid in the second fiscal year following the latest fiscal year from a defined benefit plan.

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