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REGULATION, REGULATORY FILINGS (Details) |  |  |  |  |  |  |  |  | 1 Months Ended | 4 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Oct. 01, 2016 USD ($) | Sep. 16, 2016 USD ($) | Jul. 20, 2016 USD ($) | Jun. 29, 2016 USD ($) | Dec. 24, 2015 | Nov. 13, 2015 USD ($) | Nov. 01, 2015 | Oct. 01, 2015 | Oct. 31, 2015 | Jul. 31, 2015 USD ($) | Jun. 30, 2015 USD ($) | Oct. 31, 2014 | Jul. 31, 2014 USD ($) project | Jun. 30, 2014 USD ($) | Oct. 31, 2012 USD ($) | Jun. 30, 2012 USD ($) | Feb. 29, 2016 USD ($) | Sep. 30, 2016 USD ($) station | Sep. 30, 2010 USD ($) | Sep. 30, 2015 USD ($)
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Requested base rate increase, amount |  |  | $ 112,900,000 |  |  | $ 147,600,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Composite rate of depreciation | 2.34% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Recovery period |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7 years |  |
Tax charge resulting from a change in deductibility of federal subsidies |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 2,900,000 |
Regulatory assets, noncurrent |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 441,294,000 |  | $ 410,155,000
Estimated annual bill credits |  | $ 48,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 61,600,000 |  |  |
Average residential heating customer, percent of increase (decrease) |  | (10.60%) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of NGV stations opened to the public | station |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3 |  |
Other Regulatory Asset |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory asset, maximum amount to be recorded annually |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 700,000 |  |
Regulatory asset, expense benchmark |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,400,000 |  |
Regulatory assets, threshold of recording regulatory liability when net liability exceeds amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,000,000 |  |
Other Regulatory Asset, PIM |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory assets, noncurrent |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4,400,000 |  |
SAFE Program |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capital investments approved by the BPU |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 130,000,000 |  |  |  |  |
Capital investments approved by the BPU, period |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4 years |  |  |  |  |
SAVEGREEN |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capital investments approved by the BPU |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 219,300,000 |  |
Grants, rebates and loans provided to customers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 136,600,000 |  |
Increase in regulatory funding obligations |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 20,000,000 |  |
Additional investments |  |  |  |  |  |  |  |  |  | $ 75,200,000 |  |  |  |  |  |  |  |  |  |
SAVEGREEN | Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Return on equity |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 9.75% |  |
Public utilities, approved equity capital structure, percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6.69% |  |
SAVEGREEN | Minimum | June 2012 SAVEGREEN Filing |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Program recovery term |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2 years |  |
SAVEGREEN | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Return on equity |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10.30% |  |
Public utilities, approved equity capital structure, percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7.76% |  |
SAVEGREEN | Maximum | June 2012 SAVEGREEN Filing |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Program recovery term |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10 years |  |
NJ RISE Program |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Return on equity |  |  |  |  |  |  | 9.75% |  |  |  |  |  |  |  |  |  |  |  |  |
Public utilities, approved equity capital structure, percentage |  |  |  |  |  |  | 6.74% |  |  |  |  |  |  |  |  |  |  |  |  |
Program recovery term |  |  |  |  |  |  |  |  |  |  |  |  | 5 years |  |  |  |  |  |  |
Requested rate increase (decrease), percentage |  |  |  |  |  |  | 0.07% |  |  |  |  |  |  |  |  |  |  |  |  |
Number of capital investment projects | project |  |  |  |  |  |  |  |  |  |  |  |  | 6 |  |  |  |  |  |  |
Originally filed petition for capital investments to Board of Public Utilities |  |  |  |  |  |  |  |  |  |  |  |  | $ 102,500,000 |  |  |  |  |  |  |
CIP |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Requested rate increase (decrease), percentage |  |  |  |  |  |  |  |  | 0.08% |  |  | (4.30%) |  |  |  |  |  |  |  |
BGSS |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Requested rate increase (decrease), percentage |  |  |  |  |  |  |  |  |  |  |  | (5.00%) |  |  |  |  |  |  |  |
SBC | September 2014 SBC Filing |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Requested rate increase (decrease), percentage |  |  |  |  |  |  |  |  |  |  | (3.30%) |  |  |  |  |  |  |  |  |
Approved rate, amount |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 8,500,000 |  |  |  |  |  |
SBC | December 2015 SBC Filing |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Approved rate, amount |  |  |  | $ 9,400,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
New Jersey Clean Energy Program | September 2014 SBC Filing |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Approved rate, amount |  |  |  |  |  |  |  |  |  |  | $ 16,300,000 |  |  |  |  |  |  |  |  |
USF |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Requested rate increase (decrease), percentage |  |  |  |  |  |  |  | (0.60%) |  |  |  |  |  |  |  |  |  |  |  |
NJCEP |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Requested rate increase (decrease), percentage |  |  |  |  | (0.80%) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Compressed Natural Gas Vehicle Refueling Stations |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capital investments approved by the BPU |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 10,000,000 |  |  |  |
SRL-Southern Reliability Link | Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated cost of the SRL |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 175,000,000 |  |
SRL-Southern Reliability Link | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated cost of the SRL |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 180,000,000 |  |
Subsequent Event |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Approved rate increase (decrease), amount | $ 45,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Return on equity | 9.75% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public utilities, approved equity capital structure, percentage | 52.50% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Composite rate of depreciation | 2.40% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Recovery of expenditures, approved rolling period | 7 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event | SAFE Program |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Program recovery term | 5 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capital investments approved by the BPU | $ 200,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capital Investments to be Recovered Approved By The Board Of Public Utilities | $ 157,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event | NJ RISE Program |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public utilities, approved equity capital structure, percentage | 6.90% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Program recovery term | 7 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event | CIP |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Requested rate increase (decrease), percentage | 8.20% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event | BGSS |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Requested rate increase (decrease), percentage | (5.50%) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event | USF |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Requested rate increase (decrease), percentage | 0.20% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event | LNG-Liquefied Natural Gas |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capital Investments to be Recovered Approved By The Board Of Public Utilities | $ 36,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

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