LONG-TERM DEBT (Details) - USD ($)	1 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2014	Aug. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.50%	7.50%
Proceeds from Issuance of Long-Term Debt		$ 80,000,000	$ 329,000,000
Line of Credit Facility, Maximum Borrowing Capacity	$ 610,000,000	610,000,000
Long-term Debt	1,015,300,000	1,015,300,000				$ 1,009,400,000
South Jersey Gas Company
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	210,000,000	210,000,000
South Jersey Gas Company | Line of Credit
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	200,000,000.00	200,000,000.00
Loans Payable | South Jersey Gas Company | Line of Credit
Debt Instrument [Line Items]
Proceeds from Issuance of Long-Term Debt	80,000,000
Long-term Debt	139,000,000	139,000,000
Series A Notes Due 2015, 2.39% | Senior Notes
Debt Instrument [Line Items]
Debt Instrument, Repurchase Face Amount					$ 64,000,000
Debt Instrument, Interest Rate, Stated Percentage					2.39%
Series Due 2015, 5.387% | Medium-term Notes | South Jersey Gas Company
Debt Instrument [Line Items]
Debt Instrument, Repurchase Face Amount				$ 10,000,000
Debt Instrument, Interest Rate, Stated Percentage				5.387%
September 2008 Variable Rate Demand Bonds | South Jersey Gas Company
Debt Instrument [Line Items]
Extinguishment of Debt, Amount	100,000
Debt Instrument, Face Amount	$ 25,000,000.0	$ 25,000,000.0