COMMITMENTS AND CONTINGENCIES (Details) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2005	Mar. 31, 2020	Mar. 31, 2019
Environmental
Parties who filed petitions to SCPSC order	two
Phases CAIR set omission limits to be met in	two
Number of years to meet EPA mercury and air pollutants standard	four
NPDES permit renewal permit period	five
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	19,500,000
Deferred costs net of costs previously recovered through rates and insurance settlements included in regulatory assets	$ 35,900,000
Current ownership share in New Unit	55.00%
Total additional ownership in new units	5.00%
Additional ownership in new units	1.00%		2.00%	2.00%
Number of states required to reduce emissions to attain mandated levels		28
Total Construction Milestones	146
Milestone Schedule Contingency Period	18
Completed Construction Milestones	100
MIlestones Extended	2
PSNC Energy
Environmental
Number of MGP sites requiring cleanup	5