AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS - Related Party Transactions (Details) - South Jersey Gas Company - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating Revenues/Affiliates:
Total Operating Revenues/Affiliates	$ 7,634	$ 928	$ 18,789	$ 7,724
Operations Expense/Affiliates:
Total Operations Expense/Affiliates	8,480	7,752	25,688	22,800
SJRG
Operating Revenues/Affiliates:
Total Operating Revenues/Affiliates	7,613	907	18,726	7,662
Cost of sales/affiliates	20	954	136	4,924
SJI (parent company only)
Operations Expense/Affiliates:
Total Operations Expense/Affiliates	6,294	5,832	19,390	17,082
SJIU
Operations Expense/Affiliates:
Total Operations Expense/Affiliates	1,259	1,045	3,469	2,957
Millennium
Operations Expense/Affiliates:
Total Operations Expense/Affiliates	910	857	2,772	2,598
Other
Operating Revenues/Affiliates:
Total Operating Revenues/Affiliates	21	21	63	62
Operations Expense/Affiliates:
Total Operations Expense/Affiliates	$ 17	$ 18	$ 57	$ 163