ACCUMULATED OTHER COMPREHENSIVE LOSS - Reclassifications out of AOCL (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income Taxes	$ 36,415	$ 21,870
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ (9)
Combined statutory tax rate	25.00%	40.00%
South Jersey Gas Company
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income Taxes	$ 21,836	$ 29,911
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ (9)
Combined statutory tax rate	25.00%	40.00%
Unrealized Loss in on Derivatives - Other - Interest Rate Contracts designated as cash flow hedges \| South Jersey Gas Company
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ (9)
Reclassification out of Accumulated Other Comprehensive Income \| Unrealized Loss on Derivatives-Other - interest rate contracts designated as cash flow hedges
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income Taxes	(3)
Reclassification out of Accumulated Other Comprehensive Income \| Unrealized Loss in on Derivatives - Other - Interest Rate Contracts designated as cash flow hedges \| South Jersey Gas Company
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income Taxes	(3)
Net Income (Loss) Attributable to Parent	9
Interest Charges \| Reclassification out of Accumulated Other Comprehensive Income \| Unrealized Loss on Derivatives-Other - interest rate contracts designated as cash flow hedges
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Unrealized Loss on Derivatives-Other - interest rate contracts designated as cash flow hedges	12
Interest Charges \| Reclassification out of Accumulated Other Comprehensive Income \| Unrealized Loss in on Derivatives - Other - Interest Rate Contracts designated as cash flow hedges \| South Jersey Gas Company
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Unrealized Loss on Derivatives-Other - interest rate contracts designated as cash flow hedges	$ 12

[Line Items] for Reclassification out of Accumulated Other Comprehensive Income [Table]

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount after tax of reclassification adjustments of other comprehensive income (loss).

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