FINANCIAL INSTRUMENTS - Schedule of Estimated Fair Values and Carrying Values of Long-Term Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Net of:
Finance lease, lease liability	$ 5,700	$ 5,600
Fair Value, Inputs, Level 2
Debt Instrument [Line Items]
Estimated fair values of long-term debt	3,080,970	3,653,868
Carrying amounts of long-term debt, including current maturities	3,209,067	3,255,085
Net of:
Unamortized debt issuance costs	36,399	38,462
Unamortized debt discounts	5,090	5,135
Fair Value, Inputs, Level 2 | South Jersey Gas Company
Debt Instrument [Line Items]
Estimated fair values of long-term debt	964,639	1,171,657
Carrying amounts of long-term debt, including current maturities	1,028,975	1,041,811
Net of:
Unamortized debt issuance costs	$ 8,387	$ 8,726