REGULATION - REGULATORY FILINGS (Details) - USD ($) $ in Millions		3 Months Ended
Nov. 01, 2017	Dec. 31, 2017
SAVEGREEN
Schedule of Regulatory Filings [Line Items]
Approved rate increase (decrease), amount	$ (3.9)
RAC
Schedule of Regulatory Filings [Line Items]
Requested rate increase (decrease), amount		$ (2.4)
NJCEP
Schedule of Regulatory Filings [Line Items]
Requested rate increase (decrease), amount		1.8
Natural Gas Distribution
Schedule of Regulatory Filings [Line Items]
Tax Cuts and Jobs Act of 2017, regulatory liability		228.0
Tax Cuts and Jobs Act of 2017, revaluation of deferred income taxes, provisional liability		164.3
Tax Cuts and Jobs Act of 2017, income tax effects on revaluation, provisional liability		$ 63.7

Schedule of Regulatory Filings [Line Items]

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Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Income Tax Effects On Revaluation, Provisional Liability

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Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Provisional Liability

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Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Revaluation Of Deferred Income Taxes, Provisional Liability

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Amount of public utility's approved rate increase (decrease) by regulatory agency.

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Amount of public utility's requested rate increase (decrease) with regulatory agency.

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