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REGULATION, REGULATORY FILINGS (Details) (USD $)	12 Months Ended			1 Months Ended						12 Months Ended						4 Months Ended	12 Months Ended	1 Months Ended	12 Months Ended								1 Months Ended	12 Months Ended		3 Months Ended	6 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2012	Sep. 30, 2013	Oct. 31, 2014 Subsequent Event [Member]	Sep. 30, 2014 Other Regulatory Asset Noncurrent [Member]	Sep. 30, 2013 Other Regulatory Asset Noncurrent [Member]	Sep. 30, 2014 Other Regulatory Asset Noncurrent, PIM [Member]	Sep. 30, 2014 Storm Costs [Member]	Sep. 30, 2013 Storm Costs [Member]	Sep. 30, 2014 SAVEGREEN [Member]	Sep. 30, 2014 SAVEGREEN [Member] June 2012 SAVEGREEN Filing [Member]	Sep. 30, 2014 SAVEGREEN-Incentives [Member]	Sep. 30, 2014 SAVEGREEN-Incentives [Member] June 2012 SAVEGREEN Filing [Member]	Sep. 30, 2014 CIP [Member]	Sep. 30, 2013 CIP [Member]	Sep. 30, 2013 BGSS [Member]	Sep. 30, 2014 BGSS [Member]	Oct. 31, 2014 BGSS [Member] Subsequent Event [Member]	Sep. 30, 2014 AIP I and AIP II [Member]	Sep. 30, 2014 AIP I [Member]	Sep. 30, 2014 AIP II [Member]	Sep. 30, 2014 SAFE-Safety Acceleration and Facility Enhancement Program [Member]	Sep. 30, 2014 Compressed Natural Gas Vehicle Refueling Stations [Member]	Sep. 30, 2014 NJ RISE Program [Member] project	Sep. 30, 2013 USF [Member] June 2012 USF Filing [Member]	Sep. 30, 2014 USF [Member] June 2013 USF Filing [Member]	Oct. 31, 2014 USF [Member] Subsequent Event [Member] June 2014 USF Filing [Member]	Sep. 30, 2013 SBC [Member] July 2013 SBC Filing [Member]	Sep. 30, 2014 SBC [Member] September 2014 SBC Filing [Member]	Sep. 30, 2014 New Jersey Clean Energy Program [Member]	Jun. 30, 2013 New Jersey Clean Energy Program [Member]	Jun. 30, 2014 New Jersey Clean Energy Program [Member]	Sep. 30, 2014 New Jersey Clean Energy Program [Member] July 2013 SBC Filing [Member]	Sep. 30, 2014 New Jersey Clean Energy Program [Member] September 2014 SBC Filing [Member]	Sep. 30, 2014 Minimum [Member] SAVEGREEN [Member] June 2012 SAVEGREEN Filing [Member]	Sep. 30, 2014 Minimum [Member] SAVEGREEN-Incentives [Member] June 2012 SAVEGREEN Filing [Member]	Sep. 30, 2014 Maximum [Member] SAVEGREEN [Member] June 2012 SAVEGREEN Filing [Member]	Sep. 30, 2014 Maximum [Member] SAVEGREEN-Incentives [Member] June 2012 SAVEGREEN Filing [Member]
Schedule of Regulatory [Line Items]
Program recovery term																								5 years											2 years	2 years	10 years	10 years
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
Regulatory assets, noncurrent	377,575,000		402,202,000		6,797,000	14,656,000	3,800,000	15,207,000	14,822,000
Regulatory liability, amortization period	48 years
Requested rate increase (decrease), percentage														(1.00%)	2.40%			(4.30%)							(0.10%)	(0.50%)	0.40%						1.90%
Interim rate increase (decrease), percentage																(5.20%)	(6.00%)	(5.00%)
Total investment				1,000,000,000															148,700,000				5,800,000
Reduction in the RA factor																			15,300,000
Public utilities, approved equity capital structure, percentage																				7.76%	7.12%
Return on equity																			10.30%			9.75%	10.30%
Capital investments approved by the Board of Public Utilities																						130,000,000	10,000,000
Weighted average cost of capital													6.90%									6.90%	7.10%
Public utility annual rate for allowance for funds used during construction																						6.90%
Number of capital investment projects																								6
Originally filed petition for capital investments to Board of Public Utilities																								102,500,000
Recovery amount approved by the Board of Public Utilities											85,000,000	93,100,000	17,300,000
Regulatory costs approved		308,000								52,800,000
Interest-free loans										38,800,000
Increase in tariff rider rate approved by the Board of Public Utilities													1.70%
Annual recovery amount approved by the Board of Public Utilities													12,400,000
Percent of increase (decrease) for the average residential heating customer																												(0.20%)
Approved rate, amount																												18,700,000
Requested rate increase (decrease), percentage																													(3.00%)
Requested rate, amount																													8,500,000					16,300,000
Increase in regulatory funding obligations																														15,600,000	9,800,000	15,600,000
Debt instrument, term	3 years
Maximum issuance amount	$ 300,000,000
Maximum maturity period	30 years
Credit facility, renewal period	5 years

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