REGULATORY ASSETS AND REGULATORY LIABILITIES - Regulatory Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
ETG
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	$ 198,273	$ 176,540
ETG | Excess Plant Removal Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	35,221	33,988
ETG | Excess Deferred Taxes
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	108,790	111,003
ETG | Deferred Gas Costs - Net
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	52,535	28,842
ETG | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	1,727	2,707
SJG
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	210,326	222,411
SJG | Excess Plant Removal Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	12,947	12,125
SJG | Excess Deferred Taxes
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	193,830	206,902
SJG | Deferred Gas Costs - Net
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	0	0
SJG | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	3,549	3,384
SJI
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	408,599	398,951
SJI | Excess Plant Removal Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	48,168	46,113
SJI | Excess Deferred Taxes
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	302,620	317,905
SJI | Deferred Gas Costs - Net
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	52,535	28,842
SJI | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	$ 5,276	$ 6,091