FAIR VALUE OF FINANCIAL ASSETS AND FINANCIAL LIABILITIES - Quantitative Information Regarding Significant Unobservable Inputs (Details) - Forward Contracts - Discounted Cash Flow - Level 3 - Natural Gas $ in Thousands	Sep. 30, 2022 USD ($) $ / decatherm	Dec. 31, 2021 USD ($) $ / decatherm
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Assets | $	$ 26,211	$ 8,916
Liabilities | $	28,664	8,107
SJG
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Assets | $	20,815	3,638
Liabilities | $	$ 0	$ 0
Minimum | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input	2.62	1.77
Minimum | SJG | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input	4.47	3.75
Maximum | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input	18.03	8.30
Maximum | SJG | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input	15.55	5.66
Weighted Average | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input	6.50	3.73
Weighted Average | SJG | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input	9.89	4.94