COMMITMENTS AND CONTINGENCIES (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2014
Environmental
NPDES permit renewal permit period	five
MIlestones Extended	3
ForecastedCapitalCostsApproved2012Order	$ 4,548,000,000
Regulatory Assets, Noncurrent	1,890,000,000				1,823,000,000
SCEG
Nuclear Insurance
Federal Limit on Public Liability Claims from Nuclear Incident Approximate	13,600,000,000
Maximum Insurance Coverage for each Nuclear Plant by ANI	375,000,000
Maximum liability assessment per reactor for each nuclear incident	127,300,000
Maximum Federal Limit on Public Liability Claims Per Incident for Each Year	12,600,000
Maximum yearly assessment per reactor	18,900,000
Maximum Federal Limit on Public Liability Claims per Reactor for each Nuclear Incident at 2/3	84,800,000
Inflation adjustment period for nuclear insurance	5
Maximum retrospective insurance premium per nuclear incident	43,500,000
Maximum amount of coverage to nuclear facility for property damage and outage costs	2,750,000,000
Maximum amount of coverage for accidental property damage	500,000,000
Maximum loss for a single nuclear incident	2,750,000,000
Environmental
Number of MGP decommissioned sites that contain residues of byproduct chemicals	4
Site Contingency MGP Estimated Environmental Remediation Costs	19,200,000
Deferred costs net of costs previously recovered through rates and insurance settlements included in regulatory assets	35,200,000
Current ownership share in New Unit	55.00%
Total additional ownership in new units	5.00%
Additional ownership in new units		0.00%	2.00%	1.00%
Additional ownership in new units, dollars	500,000,000
Total Construction Milestones	146
Milestone Schedule Contingency Period	18
Completed Construction Milestones	105
MIlestones Extended	3
Forecasted incremental capital costs, 2015 petition	698,000,000
Regulatory Assets, Noncurrent	1,817,000,000				1,745,000,000
PSNC Energy
Environmental
Number of MGP sites requiring cleanup	5
Regulatory Assets, Noncurrent	1,000,000
Summer Station New Units [Domain]
Nuclear Insurance
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	2,900,000,000
jointly owned utility plant ownership, construction financing cost	2,425,000,000
Environmental
Jointly Owned Utility Plant, Proportionate Ownership Share	55.00%
Nuclear Production Tax Credits	1,400,000,000
Nuclear Production Tax Credit realization period	8
Summer Station New Units [Domain] | SCEG
Environmental
Jointly Owned Utility Plant, Proportionate Ownership Share	55.00%
Nuclear Production Tax Credits	1,400,000,000
Nuclear Production Tax Credit realization period	8
Grossconstructioncosts [Member]
Environmental
ForecastedCapitalCostsApproved2012Order	5,755,000,000
Capital costs, owners [Domain]
Environmental
Forecasted incremental capital costs, 2015 petition	245,000,000
Capital costs, owners [Domain] | SCEG
Environmental
Forecasted incremental capital costs, 2015 petition	245,000,000
Capital costs, Other [Domain] [Domain]
Environmental
Forecasted incremental capital costs, 2015 petition	453,000,000
Capital costs, Other [Domain] [Domain] | SCEG
Environmental
Forecasted incremental capital costs, 2015 petition	$ 453,000,000