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DERIVATIVE INSTRUMENTS, VOLUME (Details) certificate in Thousands, $ in Millions | Sep. 30, 2016 USD ($) Bcf certificate | Sep. 30, 2015 Bcf | Jun. 01, 2015 USD ($)
--- | --- | --- | ---
Derivative [Line Items] |  |  |
Derivative, Notional Amount | $ |  |  | $ 125.0
Foreign currency contracts |  |  |
Derivative [Line Items] |  |  |
Derivative, Notional Amount | $ | $ 3.6 |  |
NJRES | Physical commodity contracts |  |  |
Derivative [Line Items] |  |  |
Number of Solar Renewable Energy Certificates (in certificates) | certificate | 148 |  |
Long | NJNG | Futures |  |  |
Derivative [Line Items] |  |  |
Outstanding long (short) derivatives (in Bcf) | 23.6 | 25.8 |
Long | NJNG | Physical |  |  |
Derivative [Line Items] |  |  |
Outstanding long (short) derivatives (in Bcf) | 9.2 | 0.0 |
Long | NJRES | Physical |  |  |
Derivative [Line Items] |  |  |
Outstanding long (short) derivatives (in Bcf) | 94.6 | 48.2 |
Long | NJRES | Financial Options |  |  |
Derivative [Line Items] |  |  |
Outstanding long (short) derivatives (in Bcf) | 1.2 | 1.2 |
Short | NJRES | Futures |  |  |
Derivative [Line Items] |  |  |
Outstanding long (short) derivatives (in Bcf) | 79.1 | 91.1 |

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