RATE AND OTHER REGULATORY MATTERS (Details) (USD $)	6 Months Ended	12 Months Ended		3 Months Ended	6 Months Ended		12 Months Ended			24 Months Ended			3 Months Ended						6 Months Ended				12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 SCEG	Jun. 30, 2013 SCEG	Jun. 30, 2012 SCEG	May 01, 2015 SCEG	Dec. 31, 2012 SCEG	Dec. 31, 2011 SCEG	May 01, 2015 SCEG	Mar. 31, 2013 SCEG	Jan. 31, 2013 SCEG	Mar. 31, 2012 PSNC Energy	Jun. 30, 2013 PSNC Energy	Jun. 30, 2013 Deferred Pollution Control Costs	Dec. 31, 2012 Deferred Pollution Control Costs	Jun. 30, 2013 Deferred Pollution Control Costs SCEG	Dec. 31, 2012 Deferred Pollution Control Costs SCEG	Jun. 30, 2013 Franchise agreement Costs	Dec. 31, 2012 Franchise agreement Costs	Jun. 30, 2013 Franchise agreement Costs SCEG	Dec. 31, 2012 Franchise agreement Costs SCEG	Dec. 31, 2012 Utility Plant [Domain]
Rate Matters [Line Items]
Regulatory Assets, Noncurrent	$ 1,439,000,000	$ 1,464,000,000		$ 1,377,000,000	$ 1,352,000,000			$ 1,377,000,000						$ 3,000,000	$ 38,000,000	$ 38,000,000	$ 38,000,000	$ 38,000,000	$ 33,000,000	$ 36,000,000	$ 33,000,000	$ 36,000,000
Amounts Recovered Through Electric Rates to offset Turbine Expenses					17,200,000
Share in Approved Capital Costs								8,000,000
Undercollected balance fuel						80,600,000
Number of coal fired units to be retired				6	2			6			6
Public Utilities, Percent Increase (Decrease) in Retail Electric Rates				4.23%		2.87%		2.30%	2.40%
Allowable return on common equity (as a percent)				10.25%	11.00%
historical average temperature								15
Demand Side Management Program Costs, Noncurrent				19,600,000	20,600,000			19,600,000	7,000,000			27,200,000
Regulatory Asset Recovery Assessments							12			24
Public Utilities Property Plant and Equipment Identifiable Capital Costs								278,000,000
Capital Cost Related to New Federal Healthcare Etc								1,000,000
Public Utilities Additional Labor Expenses for Oversight of New Units								132,000,000
Increase (decrease) in retail electric rate requested under the BLRA					67.2			0	0
Public Utilities, Percent Increase (Decrease) in Retail Natural Gas Rates		2.10%	2.10%
Public Utilities changes in Retail Natural Gas Rates Requested and Approved under RSA		0	8.6
Basis for rate calculation					12-month rolling average								12
Regulatory Noncurrent Asset Amortization Period	30				30														20				14
Public Utilities Base Fuel under Collected Balance Recovery Period	12				12	12
MPG enviromental remediatio	27
Defined Benefit Plan, Deferred Debit Attributable to Share of Regulatory Authority				$ 63,000,000				$ 63,000,000