RATES AND REGULATORY ACTIONS (Details) (USD $)	0 Months Ended	1 Months Ended											0 Months Ended	1 Months Ended										0 Months Ended	1 Months Ended		1 Months Ended									0 Months Ended	1 Months Ended									1 Months Ended													12 Months Ended	264 Months Ended			1 Months Ended
	Sep. 17, 2010	Sep. 30, 2013	Jun. 30, 2013	Feb. 28, 2013	Jul. 31, 2012	Dec. 31, 2013 customer	Oct. 31, 2013	Dec. 31, 2012 sites	Dec. 31, 2013 Environmental Restoration Costs Expended Net [Member]	Dec. 31, 2012 Environmental Restoration Costs Expended Net [Member]	Dec. 31, 2013 Other Regulatory Assets, Deferred Pipeline Integrity Costs [Member]	Dec. 31, 2012 Other Regulatory Assets, Deferred Pipeline Integrity Costs [Member]	Sep. 17, 2010 Conservation Incentive Program [Member]	Sep. 30, 2013 Conservation Incentive Program [Member]	May 31, 2013 Conservation Incentive Program [Member]	Jun. 30, 2012 Conservation Incentive Program [Member]	Jun. 30, 2011 Conservation Incentive Program [Member]	May 31, 2013 Conservation Incentive Program [Member] Non Weather [Member]	Jun. 30, 2012 Conservation Incentive Program [Member] Non Weather [Member]	Jun. 30, 2011 Conservation Incentive Program [Member] Non Weather [Member]	May 31, 2013 Conservation Incentive Program [Member] Weather [Member]	Jun. 30, 2012 Conservation Incentive Program [Member] Weather [Member]	Jun. 30, 2011 Conservation Incentive Program [Member] Weather [Member]	Sep. 17, 2010 Capital Investment Recovery Tracker [Member]	Sep. 30, 2013 Capital Investment Recovery Tracker [Member]	Oct. 31, 2012 Capital Investment Recovery Tracker [Member]	Jan. 31, 2009 Capital Investment Recovery Tracker [Member] Capital Expenditures [Member]	May 31, 2012 Capital Investment Recovery Tracker [Member] Capital Expenditures [Member]	Jun. 30, 2011 Capital Investment Recovery Tracker [Member] Capital Expenditures [Member]	Mar. 31, 2011 Capital Investment Recovery Tracker [Member] Capital Expenditures [Member]	Sep. 30, 2010 Capital Investment Recovery Tracker [Member] Capital Expenditures [Member]	Oct. 31, 2011 Capital Investment Recovery Tracker [Member] Recovered in 2012 [Member]	Oct. 31, 2011 Capital Investment Recovery Tracker [Member] Recovered in 2013 [Member]	Jan. 31, 2009 Capital Investment Recovery Tracker, 2009 Spending [Member] Capital Expenditures [Member]	Jan. 31, 2009 Capital Investment Recovery Tracker, 2010 Spending [Member] Capital Expenditures [Member]	Sep. 17, 2010 Incremental Revenue [Member]	Jan. 31, 2013 Basic Gas Supply Service [Member]	Dec. 31, 2011 Basic Gas Supply Service [Member]	Mar. 31, 2011 Basic Gas Supply Service [Member]	Sep. 30, 2013 Basic Gas Supply Service [Member]	May 31, 2013 Basic Gas Supply Service [Member]	Sep. 30, 2012 Basic Gas Supply Service [Member]	Jun. 30, 2012 Basic Gas Supply Service [Member]	Sep. 30, 2011 Basic Gas Supply Service [Member]	Jun. 30, 2011 Basic Gas Supply Service [Member]	Jan. 31, 2014 Basic Gas Supply Service [Member] Subsequent Event [Member]	Jan. 31, 2011 Energy Efficiency Tracker [Member]	Nov. 30, 2010 Energy Efficiency Tracker [Member]	Jan. 31, 2009 Energy Efficiency Tracker [Member]	Jul. 31, 2013 Energy Efficiency Tracker [Member]	Jun. 30, 2013 Energy Efficiency Tracker [Member]	May 31, 2013 Energy Efficiency Tracker [Member]	Jun. 30, 2012 Energy Efficiency Tracker [Member]	May 31, 2012 Energy Efficiency Tracker [Member]	Jun. 30, 2011 Energy Efficiency Tracker [Member]	Jul. 31, 2013 Societal Benefits Clause [Member]	Jul. 31, 2012 Societal Benefits Clause [Member]	Jul. 31, 2011 Societal Benefits Clause [Member]	Dec. 31, 2013 Remediation Adjustment Clause [Member] sites	Dec. 31, 2013 Remediation Adjustment Clause [Member] sites	Dec. 31, 2013 Remediation Adjustment Clause [Member] Environmental Restoration Costs Expended Net [Member]	Dec. 31, 2012 Remediation Adjustment Clause [Member] Environmental Restoration Costs Expended Net [Member]	Nov. 30, 2012 New Jersey Clean Energy Program [Member]	Aug. 31, 2008 New Jersey Clean Energy Program [Member]	Sep. 30, 2013 Universal Service Fund [Member]	Jun. 30, 2013 Universal Service Fund [Member]	Sep. 30, 2012 Universal Service Fund [Member]	Jun. 30, 2012 Universal Service Fund [Member]	Oct. 31, 2011 Universal Service Fund [Member]	Jun. 30, 2011 Universal Service Fund [Member]
Schedule of Capitalization [Line Items]
Public Utilities, Rate of Return on Base Rate	8.21%
Public Utilities, Return on Common Equity	10.30%
Public Utilities, Approved Base Rate Increase	$ 42,100,000												$ 16,600,000											$ 6,800,000												$ 18,700,000
Public Utilities, Annual Depreciation Reduction Attributable To Petition	1,200,000
Amount of Regulatory Costs Not yet Approved																	2,700,000	2,300,000	8,400,000	1,300,000	15,500,000	19,600,000	1,400,000			13,200,000	103,000,000	35,000,000		60,300,000		40,000,000	50,000,000	70,500,000	32,500,000						600,000		27,000,000									2,200,000	5,800,000	3,100,000	4,700,000	(6,400,000)	11,800,000	31,200,000
Amount of Regulatory Costs Not yet Approved, Percent Change in Recoveries																																											8.80%
Amount of Regulatory Costs Approved															17,800,000		2,700,000														81,300,000									600,000		27,000,000		10,600,000	10,600,000					2,100,000	24,000,000														5,800,000		8,200,000		5,400,000
Amount of Regulatory Costs Approved, Percent Change in Recoveries																													0.50%													(8.80%)		(2.90%)	(2.90%)
Proceeds from Refunds From Favorable Regulatory Action																																					9,400,000	18,700,000	21,100,000							11,200,000
Amount of Regulatory Costs Not yet Approved, Prior Year Carryover																28,000,000	2,500,000			5,200,000
Regulatory Costs, Original Recovery Period of Expenditures (in years)																											5 years
Regulatory Costs, Proposed Recovery Period of Expenditures (in years)																											2 years
Amount of Regulatory Costs Available Under Program																																																	17,000,000.0
Regulatory Costs, Period																																																	2 years
Number of sites for environmental cleanup								12																																																			12	12
Amortization Period of Environmental Remediation Costs (in years)																																																											7 years
Amount of Regulatory Costs Approved, Statewide																																																																1,200,000,000	54,400,000		78,000,000		57,400,000
Regulatory Costs For Which Reporting Entity is Responsible For																																																															7,500,000	41,500,000
Regulatory Costs For Which Reporting Entity is Responsible For, Period of Recovery (in years)																																																																4 years
Regulatory Costs, Extension Period														1 year																																	1 year	1 year															6 months
Regulatory Assets						296,081,000		352,656,000	29,945,000	37,892,000	2,800,000	1,600,000																																																	29,900,000	37,900,000
Regulated Costs Recovered																																																												92,600,000
Amount of Regulatory Costs Not yet Approved, Statewide																																																																		(29,400,000)		(500,000)		(9,300,000)
Amount of Regulatory Costs Not Yet Approved, Annual Revenue Impact																																																																		(3,700,000)		(100,000)		(800,000)
Amount of Regulatory Costs Approved, Annual Revenue Impact																																																																	3,400,000		100,000		500,000
Regulated Operations, Number of Customers Purchasing Energy Commodities From A Provider Other Then The Reporting Entity						47,074
Investment Requested to be Recovered through CIRT, Investments To Be Rolled to Base Rate						22,500,000	95,000,000																			110,600,000
Investment Requested to be Recovered through CIRT, Revenue Increase																									15,500,000.0
Investment Requested to be Recovered through CIRT III, Term of AIRP				4 years	5 years
Investment Requested to be Recovered through CIRT III, Amount of AIRP				141,200,000	250,000,000
Investment Requested to be Recovered through CIRT III, Annual Amount of AIRP				35,300,000
Investment Requested to be Recovered through SHARP		280,000,000
Investment Requested to be Recovered through SHARP, Term		7 years
Costs Requested for Deferral, Storm Related			$ 700,000