COMMITMENTS AND CONTINGENCIES - Commitments (Details) MMcf in Thousands, $ in Millions	12 Months Ended
Sep. 30, 2015 USD ($) MMcf
Long-term Purchase Commitment [Line Items]
Minimum total payments required for natural gas contracts	$ 1,369.3
Laclede Gas
Long-term Purchase Commitment [Line Items]
Minimum total payments required for natural gas contracts	600.8
Laclede Gas \| Purchase Commitment \| Subsidiary of Common Parent
Long-term Purchase Commitment [Line Items]
Annual purchase commitment	$ 1.0
Commitment termination minimum required notification period	6 months
Alagasco
Long-term Purchase Commitment [Line Items]
Minimum total payments required for natural gas contracts	$ 476.9
Alagasco \| Inventories
Long-term Purchase Commitment [Line Items]
Minimum volume purchase commitment required (in Mmcf) \| MMcf	110
Laclede Pipeline Company
Long-term Purchase Commitment [Line Items]
Ownership interest in subsidiaries	100.00%

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Purchase Commitment, Termination, Minimum Notification Period Required

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The minimum amount the entity agreed to spend under the long-term purchase commitment.

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Volume that must be purchased within the specified time period of the agreement to avoid penalties or unfavorable effects on pricing, among other adverse consequences.

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Minimum amount to be expended to satisfy the terms of arrangements in which the entity has agreed to expend funds to procure goods or services, excluding long-term purchase commitments or unconditional purchase obligations.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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