LINES OF CREDIT AND SHORT-TERM BORROWINGS - NARRATIVE (Details)		12 Months Ended
	Sep. 01, 2021 USD ($)	Dec. 31, 2021 USD ($)	Mar. 31, 2021 USD ($)
Master Revolving Credit Facility (the "Credit Agreement") | Various Lenders
Line of Credit Facility [Line Items]
Amount of facility	$ 50,000,000
Revolving Credit Facility | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Amount of facility	1,000,000,000
Additional aggregate borrowing capacity	250,000,000
Increase maximum borrowing capacity	1,250,000,000
Swingline Loan | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Amount of facility	100,000,000
Letter of Credit | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Amount of facility	350,000,000
South Jersey Industries Inc. | Revolving Credit Facility | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Maximum current borrowing capacity	500,000,000
South Jersey Gas Company | Revolving Credit Facility | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Maximum current borrowing capacity	250,000,000
ETG Utility Operations | Revolving Credit Facility | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Maximum current borrowing capacity	$ 250,000,000
Unsecured debt | South Jersey Gas commercial paper program
Line of Credit Facility [Line Items]
Amount of facility		$ 250,000,000
Unsecured debt | South Jersey Industries Inc. | Unsecured Term Loan
Line of Credit Facility [Line Items]
Amount of facility			$ 150,000,000
Unsecured debt | South Jersey Gas Company | South Jersey Gas commercial paper program
Line of Credit Facility [Line Items]
Fixed maturities of notes, which may not exceed specified number of days		270 days
Line of Credit
Line of Credit Facility [Line Items]
Amount of facility		$ 1,000,000,000
Line of Credit | Revolving Credit Facility | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Term of agreement (in years)	5 years
Line of Credit | South Jersey Industries Inc. | Line of Credit
Line of Credit Facility [Line Items]
Amount of facility		$ 500,000,000
Line of Credit | South Jersey Industries Inc. | Revolving Credit Facility
Line of Credit Facility [Line Items]
Amount of facility	$ 500,000,000
Line of Credit | South Jersey Gas Company | Revolving Credit Facility
Line of Credit Facility [Line Items]
Amount of facility	200,000,000
Line of Credit | ETG Utility Operations | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Debt covenant, ratio of indebtedness to total capitalization, maximum		0.70
Line of Credit | ETG Utility Operations | Revolving Credit Facility
Line of Credit Facility [Line Items]
Amount of facility	$ 200,000,000