LINES OF CREDIT AND SHORT-TERM BORROWINGS - Schedule of Lines of Credit (Details)	Mar. 31, 2022 USD ($)
Line of Credit
Line of Credit Facility [Line Items]
Total Facility	$ 1,000,000,000
Usage	109,000,000
Available Liquidity	891,000,000
SJI | Line of Credit | Line of Credit
Line of Credit Facility [Line Items]
Total Facility	500,000,000
Usage	60,400,000
Available Liquidity	439,600,000
Letters of credit outstanding	15,400,000
South Jersey Gas Company | Line of Credit | Line of Credit
Line of Credit Facility [Line Items]
Letters of credit outstanding	1,900,000
South Jersey Gas Company | Commercial Paper and Letters of Credit | Revolving Credit Facility
Line of Credit Facility [Line Items]
Total Facility	250,000,000
Usage	9,200,000
Available Liquidity	240,800,000
ETG | Line of Credit | Line of Credit
Line of Credit Facility [Line Items]
Letters of credit outstanding	1,000,000
ETG | Line of Credit | Revolving Credit Facility
Line of Credit Facility [Line Items]
Total Facility	250,000,000
Usage	39,400,000
Available Liquidity	$ 210,600,000