DERIVATIVE INSTRUMENTS - Fair Value of all Derivative Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Energy-related commodity contracts
Derivatives, Fair Value [Line Items]
Assets	$ 202,235	$ 117,529
Liabilities	0	0
Energy-related commodity contracts | South Jersey Gas Company
Derivatives, Fair Value [Line Items]
Assets	33,244	9,903
Liabilities	0	0
Derivatives not designated as hedging instruments under GAAP
Derivatives, Fair Value [Line Items]
Assets	202,235	117,529
Liabilities	134,156	84,081
Derivatives not designated as hedging instruments under GAAP | South Jersey Gas Company
Derivatives, Fair Value [Line Items]
Assets	33,244	9,903
Liabilities	6,612	10,844
Derivatives not designated as hedging instruments under GAAP | Energy-related commodity contracts | Derivatives - Energy Related - Current
Derivatives, Fair Value [Line Items]
Assets	150,133	95,041
Liabilities	93,458	60,002
Derivatives not designated as hedging instruments under GAAP | Energy-related commodity contracts | Derivatives - Energy Related - Current | South Jersey Gas Company
Derivatives, Fair Value [Line Items]
Assets	32,804	9,396
Liabilities	595	2,520
Derivatives not designated as hedging instruments under GAAP | Energy-related commodity contracts | Derivatives - Energy Related - Non-Current
Derivatives, Fair Value [Line Items]
Assets	52,102	22,488
Liabilities	34,681	16,079
Derivatives not designated as hedging instruments under GAAP | Energy-related commodity contracts | Derivatives - Energy Related - Non-Current | South Jersey Gas Company
Derivatives, Fair Value [Line Items]
Assets	440	507
Liabilities	0	324
Derivatives not designated as hedging instruments under GAAP | Interest rate contracts | Derivatives - Other - Current
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	435	568
Derivatives not designated as hedging instruments under GAAP | Interest rate contracts | Derivatives - Other - Current | South Jersey Gas Company
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	435	568
Derivatives not designated as hedging instruments under GAAP | Interest rate contracts | Derivatives - Other - Noncurrent
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	5,582	7,432
Derivatives not designated as hedging instruments under GAAP | Interest rate contracts | Derivatives - Other - Noncurrent | South Jersey Gas Company
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	$ 5,582	$ 7,432