FAIR VALUE MEASUREMENTS (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions | Dec. 31, 2015 | Sep. 30, 2015 | Dec. 31, 2014 |
Laclede Gas | | | |
ASSETS | | | |
Effects of Netting and Cash Margin Receivables /Payables | $ (0.1) | $ (1.3) | $ 0 |
Derivative asset | 19.9 | 19.5 | 20.2 |
LIABILITIES | | | |
Effects of Netting and Cash Margin Receivables /Payables | (17.4) | (16.7) | (20.7) |
Derivative liability | 4.6 | 5.9 | 19.5 |
Quoted Prices in Active Markets (Level 1) | Laclede Gas | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 16 | 16.8 | 16.3 |
LIABILITIES | | | |
Derivative liability before netting adjustment | 17.4 | 16.7 | 20.7 |
Significant Observable Inputs (Level 2) | Laclede Gas | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 4 | 4 | 3.9 |
LIABILITIES | | | |
Derivative liability before netting adjustment | 4.6 | 5.9 | 19.5 |
Significant Unobservable Inputs (Level 3) | Laclede Gas | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 0 | 0 | 0 |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | 0 | 0 |
U. S. stock/bond mutual funds | Laclede Gas | | | |
ASSETS | | | |
Effects of Netting and Cash Margin Receivables /Payables | 0 | 0 | 0 |
Derivative asset | 19.9 | 19.5 | 20.2 |
U. S. stock/bond mutual funds | Quoted Prices in Active Markets (Level 1) | Laclede Gas | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 15.9 | 15.5 | 16.3 |
U. S. stock/bond mutual funds | Significant Observable Inputs (Level 2) | Laclede Gas | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 4 | 4 | 3.9 |
U. S. stock/bond mutual funds | Significant Unobservable Inputs (Level 3) | Laclede Gas | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 0 | 0 | 0 |
NYMEX/ICE natural gas contracts | Laclede Gas | | | |
ASSETS | | | |
Effects of Netting and Cash Margin Receivables /Payables | (0.1) | (1.3) | |
Derivative asset | 0 | 0 | |
LIABILITIES | | | |
Effects of Netting and Cash Margin Receivables /Payables | (17.3) | (16.4) | (19.4) |
Derivative liability | 0 | 0 | 0 |
NYMEX/ICE natural gas contracts | Quoted Prices in Active Markets (Level 1) | Laclede Gas | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 0.1 | 1.3 | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 17.3 | 16.4 | 19.4 |
NYMEX/ICE natural gas contracts | Significant Observable Inputs (Level 2) | Laclede Gas | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 0 | 0 | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | 0 | 0 |
NYMEX/ICE natural gas contracts | Significant Unobservable Inputs (Level 3) | Laclede Gas | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 0 | 0 | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | 0 | 0 |
OTCBB natural gas contracts | Laclede Gas | | | |
LIABILITIES | | | |
Effects of Netting and Cash Margin Receivables /Payables | 0 | 0 | 0 |
Derivative liability | 4.6 | 5.9 | 19.5 |
OTCBB natural gas contracts | Quoted Prices in Active Markets (Level 1) | Laclede Gas | | | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | 0 | 0 |
OTCBB natural gas contracts | Significant Observable Inputs (Level 2) | Laclede Gas | | | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 4.6 | 5.9 | 19.5 |
OTCBB natural gas contracts | Significant Unobservable Inputs (Level 3) | Laclede Gas | | | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | 0 | 0 |
NYMEX gasoline and heating oil contracts | Laclede Gas | | | |
LIABILITIES | | | |
Effects of Netting and Cash Margin Receivables /Payables | | (0.3) | |
Derivative liability | | 0 | |
NYMEX gasoline and heating oil contracts | Quoted Prices in Active Markets (Level 1) | Laclede Gas | | | |
LIABILITIES | | | |
Derivative liability before netting adjustment | | 0.3 | |
NYMEX gasoline and heating oil contracts | Significant Observable Inputs (Level 2) | Laclede Gas | | | |
LIABILITIES | | | |
Derivative liability before netting adjustment | | 0 | |
NYMEX gasoline and heating oil contracts | Significant Unobservable Inputs (Level 3) | Laclede Gas | | | |
LIABILITIES | | | |
Derivative liability before netting adjustment | | 0 | |
Gasoline and heating oil contracts | Laclede Gas | | | |
LIABILITIES | | | |
Effects of Netting and Cash Margin Receivables /Payables | (0.1) | | (1.3) |
Derivative liability | 0 | | 0 |
Gasoline and heating oil contracts | Quoted Prices in Active Markets (Level 1) | Laclede Gas | | | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0.1 | | 1.3 |
Gasoline and heating oil contracts | Significant Observable Inputs (Level 2) | Laclede Gas | | | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | | 0 |
Gasoline and heating oil contracts | Significant Unobservable Inputs (Level 3) | Laclede Gas | | | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | | 0 |
Gas Utility | | | |
ASSETS | | | |
Effects of Netting and Cash Margin Receivables /Payables | (0.1) | (1.3) | |
Derivative asset | 19.9 | 19.5 | |
LIABILITIES | | | |
Effects of Netting and Cash Margin Receivables /Payables | (17.4) | (16.7) | (20.7) |
Derivative liability | 4.6 | 5.9 | 19.5 |
Gas Utility | Quoted Prices in Active Markets (Level 1) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 16 | 16.8 | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 17.4 | 16.7 | 20.7 |
Gas Utility | Significant Observable Inputs (Level 2) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 4 | 4 | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 4.6 | 5.9 | 19.5 |
Gas Utility | Significant Unobservable Inputs (Level 3) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 0 | 0 | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | 0 | 0 |
Gas Utility | U. S. stock/bond mutual funds | | | |
ASSETS | | | |
Effects of Netting and Cash Margin Receivables /Payables | 0 | 0 | 0 |
Derivative asset | 19.9 | 19.5 | 20.2 |
Gas Utility | U. S. stock/bond mutual funds | Quoted Prices in Active Markets (Level 1) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 15.9 | 15.5 | 16.3 |
Gas Utility | U. S. stock/bond mutual funds | Significant Observable Inputs (Level 2) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 4 | 4 | 3.9 |
Gas Utility | U. S. stock/bond mutual funds | Significant Unobservable Inputs (Level 3) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 0 | 0 | 0 |
Gas Utility | NYMEX/ICE natural gas contracts | | | |
ASSETS | | | |
Effects of Netting and Cash Margin Receivables /Payables | (0.1) | (1.3) | |
Derivative asset | 0 | 0 | |
LIABILITIES | | | |
Effects of Netting and Cash Margin Receivables /Payables | (17.3) | (16.4) | (19.4) |
Derivative liability | 0 | 0 | 0 |
Gas Utility | NYMEX/ICE natural gas contracts | Quoted Prices in Active Markets (Level 1) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 0.1 | 1.3 | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 17.3 | 16.4 | 19.4 |
Gas Utility | NYMEX/ICE natural gas contracts | Significant Observable Inputs (Level 2) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 0 | 0 | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | 0 | 0 |
Gas Utility | NYMEX/ICE natural gas contracts | Significant Unobservable Inputs (Level 3) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 0 | 0 | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | 0 | 0 |
Gas Utility | OTCBB natural gas contracts | | | |
LIABILITIES | | | |
Effects of Netting and Cash Margin Receivables /Payables | 0 | 0 | 0 |
Derivative liability | 4.6 | 5.9 | 19.5 |
Gas Utility | OTCBB natural gas contracts | Quoted Prices in Active Markets (Level 1) | | | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | 0 | 0 |
Gas Utility | OTCBB natural gas contracts | Significant Observable Inputs (Level 2) | | | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 4.6 | 5.9 | 19.5 |
Gas Utility | OTCBB natural gas contracts | Significant Unobservable Inputs (Level 3) | | | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | 0 | 0 |
Gas Utility | NYMEX gasoline and heating oil contracts | | | |
LIABILITIES | | | |
Effects of Netting and Cash Margin Receivables /Payables | (0.1) | (0.3) | (1.3) |
Derivative liability | 0 | 0 | 0 |
Gas Utility | NYMEX gasoline and heating oil contracts | Quoted Prices in Active Markets (Level 1) | | | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0.1 | 0.3 | 1.3 |
Gas Utility | NYMEX gasoline and heating oil contracts | Significant Observable Inputs (Level 2) | | | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | 0 | 0 |
Gas Utility | NYMEX gasoline and heating oil contracts | Significant Unobservable Inputs (Level 3) | | | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | 0 | 0 |
Gas Marketing | | | |
ASSETS | | | |
Effects of Netting and Cash Margin Receivables /Payables | | (8.4) | |
Derivative asset | | 24.7 | |
LIABILITIES | | | |
Effects of Netting and Cash Margin Receivables /Payables | (22.7) | (22.3) | (28.9) |
Derivative liability | 5.7 | 7.6 | 20.3 |
Gas Marketing | Quoted Prices in Active Markets (Level 1) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | | 23.1 | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 18.9 | 17.9 | 24.1 |
Gas Marketing | Significant Observable Inputs (Level 2) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | | 9.8 | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 9.5 | 12 | 25.1 |
Gas Marketing | Significant Unobservable Inputs (Level 3) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | | 0.2 | |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | 0 | 0 |
Gas Marketing | U. S. stock/bond mutual funds | | | |
ASSETS | | | |
Effects of Netting and Cash Margin Receivables /Payables | (7.3) | | (4.6) |
Derivative asset | 24.7 | | 26.3 |
Gas Marketing | U. S. stock/bond mutual funds | Quoted Prices in Active Markets (Level 1) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 20.1 | | 21.7 |
Gas Marketing | U. S. stock/bond mutual funds | Significant Observable Inputs (Level 2) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 11.7 | | 9 |
Gas Marketing | U. S. stock/bond mutual funds | Significant Unobservable Inputs (Level 3) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 0.2 | | 0.2 |
Gas Marketing | NYMEX/ICE natural gas contracts | | | |
ASSETS | | | |
Effects of Netting and Cash Margin Receivables /Payables | (6.9) | (6.6) | (4.3) |
Derivative asset | 3 | 4 | 2.1 |
LIABILITIES | | | |
Effects of Netting and Cash Margin Receivables /Payables | (5) | (5.1) | (7.9) |
Derivative liability | 0 | 0 | 0 |
Gas Marketing | NYMEX/ICE natural gas contracts | Quoted Prices in Active Markets (Level 1) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 4.1 | 6.3 | 5.4 |
LIABILITIES | | | |
Derivative liability before netting adjustment | 1.5 | 1.2 | 3.4 |
Gas Marketing | NYMEX/ICE natural gas contracts | Significant Observable Inputs (Level 2) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 5.8 | 4.3 | 1 |
LIABILITIES | | | |
Derivative liability before netting adjustment | 3.5 | 3.9 | 4.5 |
Gas Marketing | NYMEX/ICE natural gas contracts | Significant Unobservable Inputs (Level 3) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 0 | 0 | 0 |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | 0 | 0 |
Gas Marketing | Natural gas commodity contracts | | | |
ASSETS | | | |
Effects of Netting and Cash Margin Receivables /Payables | (0.3) | (0.5) | (0.3) |
Derivative asset | 1.8 | 1.2 | 4 |
LIABILITIES | | | |
Effects of Netting and Cash Margin Receivables /Payables | (0.3) | (0.5) | (0.3) |
Derivative liability | 1.1 | 1.7 | 0.8 |
Gas Marketing | Natural gas commodity contracts | Quoted Prices in Active Markets (Level 1) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 0 | 0 | 0 |
LIABILITIES | | | |
Derivative liability before netting adjustment | 0 | 0 | 0 |
Gas Marketing | Natural gas commodity contracts | Significant Observable Inputs (Level 2) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 1.9 | 1.5 | 4.1 |
LIABILITIES | | | |
Derivative liability before netting adjustment | 1.4 | 2.2 | 1.1 |
Gas Marketing | Natural gas commodity contracts | Significant Unobservable Inputs (Level 3) | | | |
ASSETS | | | |
Derivative asset before netting adjustment | 0.2 | 0.2 | 0.2 |
LIABILITIES | | | |
Derivative liability before netting adjustment | $ 0 | $ 0 | $ 0 |