FINANCIAL INSTRUMENTS - Cash, Cash Equivalents and Restricted Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Line Items]
Cash and Cash Equivalents	$ 32,522	$ 28,754
Restricted Investments	84	686
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	32,606	29,440	$ 31,868	$ 41,831
South Jersey Gas Company
Cash and Cash Equivalents [Line Items]
Cash and Cash Equivalents	3,234	3,360
Restricted Investments	34	686
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 3,268	$ 4,046	$ 17,466	$ 6,424