FINANCIAL INSTRUMENTS - SCHEDULE OF ESTIMATED FAIR VALUES AND CARRYING VALUES OF LONG-TERM DEBT (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Carrying amounts of long-term debt, including current maturities (A)	$ 3,293,037	$ 2,950,946
Unamortized debt issuance costs	38,500	29,600
Unamortized debt discounts	5,100	5,200
Finance lease, lease liability	5,638	3,053
Level 2
Debt Instrument [Line Items]
Estimated fair values of long-term debt	3,653,868	3,152,224
Carrying amounts of long-term debt, including current maturities (A)	3,255,085	2,919,201
Unamortized debt issuance costs	38,462	29,574
Unamortized debt discounts	5,135	5,224
South Jersey Gas Company
Debt Instrument [Line Items]
Carrying amounts of long-term debt, including current maturities (A)	1,050,537	1,078,446
Unamortized debt issuance costs	8,700	9,400
South Jersey Gas Company | Level 2
Debt Instrument [Line Items]
Estimated fair values of long-term debt	1,171,657	1,197,052
Carrying amounts of long-term debt, including current maturities (A)	1,041,811	1,069,089
Unamortized debt issuance costs	$ 8,726	$ 9,357