PENSION AND OTHER POSTRETIREMENT BENEFITS - ESTIMATED COSTS THAT WILL BE AMORTIZED (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)
Pension Benefits
Regulatory Assets into Net Periodic Benefit Costs
Prior Service Cost/(Credit)	$ 63
Net Actuarial Loss	2,839
Accumulated Other Comprehensive Income (Loss) into Net Periodic Benefit Costs
Prior Service Cost/(Credit)	7
Net Actuarial Loss	4,246
Other Postretirement Benefits
Regulatory Assets into Net Periodic Benefit Costs
Prior Service Cost/(Credit)	(502)
Net Actuarial Loss	100
Accumulated Other Comprehensive Income (Loss) into Net Periodic Benefit Costs
Prior Service Cost/(Credit)	(107)
Net Actuarial Loss	40
South Jersey Gas Company | Pension Benefits
Regulatory Assets into Net Periodic Benefit Costs
Prior Service Cost/(Credit)	63
Net Actuarial Loss	2,839
Accumulated Other Comprehensive Income (Loss) into Net Periodic Benefit Costs
Prior Service Cost/(Credit)	0
Net Actuarial Loss	3,278
South Jersey Gas Company | Other Postretirement Benefits
Regulatory Assets into Net Periodic Benefit Costs
Prior Service Cost/(Credit)	(502)
Net Actuarial Loss	100
Accumulated Other Comprehensive Income (Loss) into Net Periodic Benefit Costs
Prior Service Cost/(Credit)	0
Net Actuarial Loss	$ 0