RATE AND OTHER REGULATORY MATTERS (Details) $ in Millions	3 Months Ended			6 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2015 USD ($) MW	Jun. 30, 2014 USD ($)	Mar. 31, 2014	Jun. 30, 2015 USD ($) MW	Jun. 30, 2014 USD ($)	Sep. 30, 2014	Dec. 31, 2015	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Jun. 30, 2013 USD ($)	Dec. 31, 2012
Rate Matters [Line Items]
Carrying cost recovery				$ (6.0)	$ (4.0)
Regulatory Assets, Noncurrent	$ 1,798.0			$ 1,798.0				$ 1,823.0
Public Utilities Base Fuel under Collected Balance Recovery Period				12
Allowable Return On Equity For New Nuclear Construction, Prior to January 1, 2016				10.00%
Allowable Return On Equity For New Nuclear Construction, After January 1, 2016				10.00%
SCEG
Rate Matters [Line Items]
Forecasted incremental capital costs, 2015 petition				$ 698.0
Forecasted Capital Cost, 2015 Petition				5,200.0
Amounts Recovered Through Electric Rates to offset Nuclear Related Outage Costs				$ 17.2
Fuel Costs		$ 10.3
Undercollected balance fuel		46.0			46.0
Capacity of renewable energy facilities by 2020 | MW	85			85
Capacity of renewable energy facilities by 2016 | MW	30			30
Carrying costs on deferred income tax assets	$ 2.2	1.4		$ 4.1	2.5
Carrying cost recovery				(6.0)	(4.0)
Regulatory Assets, Noncurrent	$ 1,724.0			$ 1,724.0				1,745.0
Number of coal fired units to be retired	3			3							6
Allowable return on common equity (as a percent)				11.00%
Demand Side Management Program Costs, Noncurrent	$ 32.0	$ 15.4		$ 32.0	$ 15.4					$ 16.9
Increase (decrease) in retail electric rate requested under the BLRA				$ 65.0				$ 66.0	$ 67.2
Public Utilities, Percent Increase (Decrease) in Retail Electric Rates								0.00%	2.90%
Public Utilities, Percent Increase (Decrease) in Retail Natural Gas Rates								0.60%
Public Utilities changes in Retail Natural Gas Rates Approved under RSA								$ 2.6
Public Utilities, Rate Calculation Basis				12-month rolling average
Public Utilities Base Fuel under Collected Balance Recovery Period				12
Derivative, Gain on Derivative								17.8
Storm Damage Reserve Cost Applied								5.0
Number of Units retired	3			3					3
Demand side management recovery period				5
Amount Allowed to be Recovered through Electric Rates to Offset Incremental Storm Damage Costs				$ 100.0
Allowable Return On Equity For New Nuclear Construction, Prior to January 1, 2016				10.00%
Allowable Return On Equity For New Nuclear Construction, After January 1, 2016				10.00%
PSNC Energy
Rate Matters [Line Items]
Public Utilities, Rate Calculation Basis			12
Pension costs, electric [Member] | SCEG
Rate Matters [Line Items]
Regulatory Noncurrent Asset Amortization Period				30
Defined Benefit Plan, Deferred Debit Attributable to Share of Regulatory Authority	$ 63.0			$ 63.0
Pension Costs [Member]
Rate Matters [Line Items]
Regulatory Assets, Noncurrent	332.0			332.0				350.0
Pension Costs [Member] | SCEG
Rate Matters [Line Items]
Regulatory Assets, Noncurrent	300.0			$ 300.0				310.0
Regulatory Noncurrent Asset Amortization Period				12					30
Other Regulatory Assets [Member]
Rate Matters [Line Items]
Regulatory Assets, Noncurrent	41.0			$ 41.0				35.0
Regulatory Noncurrent Asset Amortization Period				30		30
Other Regulatory Assets [Member] | SCEG
Rate Matters [Line Items]
Regulatory Assets, Noncurrent								35.0
Regulatory Noncurrent Asset Amortization Period				50			50
Deferred Pollution Control Costs
Rate Matters [Line Items]
Regulatory Assets, Noncurrent	35.0			$ 35.0				36.0
Deferred Pollution Control Costs | SCEG
Rate Matters [Line Items]
Regulatory Assets, Noncurrent	35.0			35.0				36.0
Franchise agreement Costs
Rate Matters [Line Items]
Regulatory Assets, Noncurrent	24.0			24.0				26.0
Franchise agreement Costs | SCEG
Rate Matters [Line Items]
Regulatory Assets, Noncurrent	$ 24.0			24.0				$ 26.0
Capital costs, construction delays [Domain] | SCEG
Rate Matters [Line Items]
Forecasted incremental capital costs, 2015 petition				539.0
Grossconstructioncosts [Member] | SCEG
Rate Matters [Line Items]
Forecasted Capital Cost, 2015 Petition				6,800.0
Planned major maintenance [Member] | SCEG
Rate Matters [Line Items]
Amounts Recovered through Electric Rates to offset Turbine Expense				18.4
Storm damage reserve [Member]
Rate Matters [Line Items]
Amount Allowed to be Recovered through Electric Rates to Offset Incremental Storm Damage Costs				$ 100.0