SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Asset Management and Supply Service Agreements
Property, Plant and Equipment, Net	$ 285	$ 284
SCEG
Significant Accounting Policies
Number of coal fired units to be retired	3			6
Number of Units retired	3		3
Asset Management and Supply Service Agreements
Property, Plant and Equipment, Net	67	67
Genco
Significant Accounting Policies
Power Generation Capacity Megawatts	605
Asset Management and Supply Service Agreements
Property, Plant and Equipment, Net	498
PSNC Energy [Member]
Asset Management and Supply Service Agreements
Percentage of natural gas inventory held by counterparties under asset management and supply service agreements (as a percent)	32.00%	48.00%
Natural gas inventory, carrying amount	$ 8.7	$ 26.1
PercentOfStorageFeesCreditedToRatePayers	75.00%