FINANCIAL INSTRUMENTS - NARRATIVE (Details) - South Jersey Gas Company - Financing receivable - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term of loans (in years)	5 years
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term of loans (in years)	10 years
Level 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Long-term receivables, net of unamortized discount	$ 1.7	$ 2.5
Loans for upgrading equipment for energy efficiency	55.4	46.4
Loans for upgrading equipment for energy efficiency, current	11.1	6.4
Loans for upgrading equipment for energy efficiency, noncurrent	$ 44.3	$ 40.0
Level 2 | Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans for upgrading equipment for energy efficiency, term (in years)	2 years
Level 2 | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans for upgrading equipment for energy efficiency, term (in years)	10 years