DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Fair Value of Derivative Instruments (Details) (USD $)
In Millions, unless otherwise specified |
Sep. 30, 2014
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Sep. 30, 2013
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | $ 7.7 | [1] | $ 6.3 | [1] | ||
Fair value of liability derivatives presented above | 12.0 | [1] | 10.6 | [1] | ||
Gas Utility | Not Designated as Hedging Instrument
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 2.5 | [1] | 1.7 | [1] | ||
Fair value of liability derivatives presented above | 9.3 | [1] | 8.9 | [1] | ||
Gas Utility | Gasoline and heating oil contracts | Designated as Hedging Instrument | Accounts Receivable – Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0 | [1] | 0.1 | [1] | ||
Fair value of liability derivatives presented above | 0.2 | [1] | 0 | [1] | ||
Gas Utility | Gasoline and heating oil contracts | Not Designated as Hedging Instrument | Accounts Receivable – Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0 | [1] | ||||
Fair value of liability derivatives presented above | 0.4 | [1] | ||||
Gas Utility | Natural gas contracts | Not Designated as Hedging Instrument | Accounts Receivable – Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 2.4 | [1] | 1.5 | [1] | ||
Fair value of liability derivatives presented above | 5.2 | [1] | 3.5 | [1] | ||
Gas Utility | Natural gas contracts | Not Designated as Hedging Instrument | Prepayments and other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0 | [1] | 0 | [1] | ||
Fair value of liability derivatives presented above | 0 | [1] | 0 | [1] | ||
Gas Utility | Natural gas contracts | Not Designated as Hedging Instrument | Derivative Asset Instruments
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0.1 | [1] | ||||
Fair value of liability derivatives presented above | 3.7 | [1] | ||||
Gas Utility | Natural gas contracts | Not Designated as Hedging Instrument | Deferred Charges - Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0 | [1] | ||||
Fair value of liability derivatives presented above | 0 | [1] | ||||
Gas Utility | Natural gas contracts | Not Designated as Hedging Instrument | Current Liabilities - Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0.2 | [1] | ||||
Fair value of liability derivatives presented above | 4.0 | [1] | ||||
Gas Utility | Natural gas contracts | Not Designated as Hedging Instrument | Deferred Credits and Other Liabilities - Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0 | [1] | ||||
Fair value of liability derivatives presented above | 1.4 | [1] | ||||
Gas Marketing | Designated as Hedging Instrument
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 1.4 | [1] | 2.3 | [1] | ||
Fair value of liability derivatives presented above | 0.8 | [1] | 0.5 | [1] | ||
Gas Marketing | Not Designated as Hedging Instrument
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 3.8 | [1] | 2.3 | [1] | ||
Fair value of liability derivatives presented above | 1.9 | [1] | 1.2 | [1] | ||
Gas Marketing | Natural gas contracts | Designated as Hedging Instrument | Prepayments and other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0 | [1] | 2.2 | [1] | ||
Fair value of liability derivatives presented above | 0 | [1] | 0.5 | [1] | ||
Gas Marketing | Natural gas contracts | Designated as Hedging Instrument | Derivative Asset Instruments
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0.7 | [1] | ||||
Fair value of liability derivatives presented above | 0.4 | [1] | ||||
Gas Marketing | Natural gas contracts | Designated as Hedging Instrument | Deferred Charges - Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0.7 | [1] | 0 | [1] | ||
Fair value of liability derivatives presented above | 0.2 | [1] | 0 | [1] | ||
Gas Marketing | Natural gas contracts | Not Designated as Hedging Instrument | Accounts Receivable – Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0 | [1] | ||||
Fair value of liability derivatives presented above | 0 | [1] | ||||
Gas Marketing | Natural gas contracts | Not Designated as Hedging Instrument | Prepayments and other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0 | [1] | 1.9 | [1] | ||
Fair value of liability derivatives presented above | 0 | [1] | 0.2 | [1] | ||
Gas Marketing | Natural gas contracts | Not Designated as Hedging Instrument | Derivative Asset Instruments
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 3.5 | [1] | ||||
Fair value of liability derivatives presented above | 1.4 | [1] | ||||
Gas Marketing | Natural gas contracts | Not Designated as Hedging Instrument | Deferred Charges - Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0.3 | [1] | 0.1 | [1] | ||
Fair value of liability derivatives presented above | 0 | [1] | 0.1 | [1] | ||
Gas Marketing | Natural gas contracts | Not Designated as Hedging Instrument | Current Liabilities - Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0 | [1] | 0.3 | [1] | ||
Fair value of liability derivatives presented above | 0.5 | [1] | 0.8 | [1] | ||
Gas Marketing | Natural gas contracts | Not Designated as Hedging Instrument | Deferred Credits and Other Liabilities - Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0 | [1] | 0 | [1] | ||
Fair value of liability derivatives presented above | 0 | [1] | 0.1 | [1] | ||
Laclede Gas
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 2.5 | 1.8 | ||||
Fair value of liability derivatives presented above | 9.5 | 8.9 | ||||
Laclede Gas | Gas Utility
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 2.5 | 1.8 | ||||
Fair value of liability derivatives presented above | 9.5 | 8.9 | ||||
Laclede Gas | Gas Utility | Designated as Hedging Instrument
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0 | 0.1 | ||||
Fair value of liability derivatives presented above | 0.2 | 0 | ||||
Laclede Gas | Gas Utility | Not Designated as Hedging Instrument
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 2.5 | 1.7 | ||||
Fair value of liability derivatives presented above | 9.3 | 8.9 | ||||
Laclede Gas | Gas Utility | Gasoline and heating oil contracts | Designated as Hedging Instrument | Accounts Receivable – Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0 | 0.1 | ||||
Fair value of liability derivatives presented above | 0.2 | 0 | ||||
Laclede Gas | Gas Utility | Gasoline and heating oil contracts | Not Designated as Hedging Instrument | Accounts Receivable – Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0 | |||||
Fair value of liability derivatives presented above | 0.4 | |||||
Laclede Gas | Gas Utility | Natural gas contracts | Not Designated as Hedging Instrument | Accounts Receivable – Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 2.4 | 1.5 | ||||
Fair value of liability derivatives presented above | 5.2 | 3.5 | ||||
Laclede Gas | Gas Utility | Natural gas contracts | Not Designated as Hedging Instrument | Prepayments and other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0 | 0 | ||||
Fair value of liability derivatives presented above | 0 | 0 | ||||
Laclede Gas | Gas Utility | Natural gas contracts | Not Designated as Hedging Instrument | Derivative Asset Instruments
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0.1 | |||||
Fair value of liability derivatives presented above | 3.7 | |||||
Laclede Gas | Gas Utility | Natural gas contracts | Not Designated as Hedging Instrument | Deferred Charges - Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0 | [1] | 0 | |||
Fair value of liability derivatives presented above | 0 | [1] | 0 | |||
Laclede Gas | Gas Utility | Natural gas contracts | Not Designated as Hedging Instrument | Current Liabilities - Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0.2 | |||||
Fair value of liability derivatives presented above | 4.0 | |||||
Laclede Gas | Gas Utility | Natural gas contracts | Not Designated as Hedging Instrument | Deferred Credits and Other Liabilities - Other
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Derivatives, Fair Value [Line Items] | ||||||
Fair value of asset derivatives presented above | 0 | |||||
Fair value of liability derivatives presented above | $ 1.4 | |||||
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