SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended						37 Months Ended	6 Months Ended
	Dec. 31, 2011 M	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 SCE&G M Y	Dec. 31, 2010 SCE&G	Dec. 31, 2009 SCE&G	Jul. 31, 2011 SCE&G	Dec. 31, 2011 SCE&G Numerator	Dec. 31, 2011 CGT	Dec. 31, 2011 PSNC Energy
Major Maintenance
Amount authorized to be collected annually through electric rates to offset certain turbine maintenance expenditure				$ 18.4
Turbine maintenance cost				11.5
Duration between successive nuclear outages (in months)				18
Monthly accruals for nuclear refueling outages							1.2	1.2
Nuclear refueling outage costs	34.1		32.7	22.7		21.8
Nuclear refueling outage costs accrued				7.2	14.3
Goodwill
Carrying value of goodwill	230	230							20	210
Nuclear Decommissioning
Entity's share in nuclear decommissioning cost for Summer Station Unit 1 (as a percent)				66.67%
Nuclear decommissioning costs for Summer Station Unit 1				451.0
Santee Cooper's share in nuclear decommissioning cost at Summer Station Unit 1 (as a percent)				33.33%
Estimated safe store status period (in years)				P60Y
Amount collected for decommissioning cost through rates				3.2	3.2	3.2
Cash and Cash Equivalent
Maximum original maturity period of cash investments to be considered as cash equivalent (in months)	3
Accounts Receivable
Maximum duration for which receivables are due from receipt of invoice (in months)	1
Asset Management and Supply Service Agreements
Percentage of natural gas inventory held by counterparties under asset management and supply service agreements (as a percent)										45.00%
Natural gas inventory, carrying amount										28.7
Revenue Recognition
Unbilled revenue from electricity and natural gas delivered	$ 169.1	$ 221.1
Duration for which an eWNA was implemented on a pilot basis (in years)				1
Earnings Per Share
Weighted Average Shares Outstanding - Basic (in shares)	128.8	125.7	122.1
Net effect of dilutive stock-based compensation plans and equity forward contracts (in shares)	1.4	0.6	0.1
Weighted Average Number of Shares Outstanding, Diluted	130.2	126.3	122.2