REGULATORY ASSETS AND REGULATORY LIABILITIES - Regulatory Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
South Jersey Gas Company
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	$ 217,866	$ 222,411
South Jersey Gas Company | Excess Plant Removal Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	12,392	12,125
South Jersey Gas Company | Excess Deferred Taxes
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	199,350	206,902
South Jersey Gas Company | Deferred Gas Costs - Net
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	0	0
South Jersey Gas Company | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	6,124	3,384
SJI
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	443,639	398,951
SJI | Excess Plant Removal Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	47,218	46,113
SJI | Excess Deferred Taxes
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	309,615	317,905
SJI | Deferred Gas Costs - Net
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	75,416	28,842
SJI | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	11,390	6,091
ETG Utility Operations
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	225,773	176,540
ETG Utility Operations | Excess Plant Removal Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	34,826	33,988
ETG Utility Operations | Excess Deferred Taxes
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	110,265	111,003
ETG Utility Operations | Deferred Gas Costs - Net
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	75,416	28,842
ETG Utility Operations | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	$ 5,266	$ 2,707