REGULATORY ASSETS AND REGULATORY LIABILITIES - NARRATIVE (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
South Jersey Gas Company
Regulatory Assets [Line Items]
Regulatory assets	$ 482,745	$ 495,084
Deferral of costs related to expected credit losses from uncollectibles	$ 6,800
South Jersey Gas Company | Environmental restoration costs
Regulatory Assets [Line Items]
Original recovery period of expenditures (in years)	7 years
South Jersey Gas Company | Deferred Pension and Other Postretirement Benefit Costs
Regulatory Assets [Line Items]
Regulatory assets	$ 47,504	77,426
South Jersey Gas Company | Judicial Ruling | Pricing dispute, long-term gas supply contract
Regulatory Assets [Line Items]
Amount paid to third party supplier	21,300	22,900
ETG Utility Operations
Regulatory Assets [Line Items]
Regulatory assets	189,671	178,908
ETG Utility Operations | Environmental Remediation Costs: Insurance Recovery Receivables
Regulatory Assets [Line Items]
Regulatory assets	20,400
Increase (decrease) in regulatory assets		13,600
ETG Utility Operations | Deferred Pension and Other Postretirement Benefit Costs
Regulatory Assets [Line Items]
Regulatory assets	$ 813	$ 8,466
Amortization period (in years)	15 years
ETG Utility Operations | Other Postretirement Benefits
Regulatory Assets [Line Items]
Amortization period (in years)	9 years 2 months 12 days