RATE AND OTHER REGULATORY MATTERS (Details 2) $ in Millions	3 Months Ended			6 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Sep. 30, 2014	Dec. 31, 2015	Dec. 31, 2014 USD ($)	Dec. 31, 2013	Jun. 30, 2013 USD ($)
Regulatory Assets
Regulatory Liabilities	$ 885.0			$ 885.0				$ 814.0
Public Utilities Base Fuel under Collected Balance Recovery Period				12
Regulatory Assets, Noncurrent	1,798.0			$ 1,798.0				$ 1,823.0
SCEG
Regulatory Assets
Public Utilities, Rate Calculation Basis				12-month rolling average
Fuel Costs		$ 10.3
Undercollected balance fuel		46.0			$ 46.0
Public Utilities, Percent Increase (Decrease) in Retail Natural Gas Rates								0.60%
Regulatory Liabilities	674.0			$ 674.0				$ 610.0
Annual Storm Damage Costs not offset by Amounts Recovered through Electric Rates				2.5
Carrying costs on deferred income tax assets	2.2	1.4		4.1	2.5
Derivative, Gain on Derivative								17.8
Storm Damage Reserve Cost Applied								5.0
Demand Side Management Program Costs, Noncurrent	32.0	$ 15.4		32.0	$ 15.4					$ 16.9
Amount Allowed to be Recovered through Electric Rates to Offset Incremental Storm Damage Costs				$ 100.0
Public Utilities Base Fuel under Collected Balance Recovery Period				12
Regulatory Assets, Noncurrent	1,724.0			$ 1,724.0				1,745.0
Demand side management recovery period				5
Storm Damage Reserve Applied To Offset Net Lost Margin Related To DSM			$ 5.0
Public Utilities changes in Retail Natural Gas Rates Approved under RSA								2.6
Amounts Recovered Through Electric Rates to offset Nuclear Related Outage Costs				$ 17.2
Public Utilities, Authorized Allowable Return on Common Equity, Percentage				11.00%
PSNC Energy [Member]
Regulatory Assets
Public Utilities, Rate Calculation Basis			12
Other Regulatory Liability [Member]
Regulatory Assets
Regulatory Liabilities	0.0			$ 0.0				1.0
Asset Retirement Obligation Costs [Member]
Regulatory Assets
Regulatory Liabilities	720.0			720.0				703.0
Asset Retirement Obligation Costs [Member] | SCEG
Regulatory Assets
Regulatory Liabilities	514.0			514.0				505.0
Deferred Income Tax Charges [Member]
Regulatory Assets
Regulatory Liabilities	21.0			21.0				22.0
Deferred Income Tax Charges [Member] | SCEG
Regulatory Assets
Regulatory Liabilities	16.0			16.0				17.0
Storm damage reserve [Member]
Regulatory Assets
Regulatory Liabilities	6.0			6.0				6.0
Annual Storm Damage Costs not offset by Amounts Recovered through Electric Rates				2.5
Amount Allowed to be Recovered through Electric Rates to Offset Incremental Storm Damage Costs				100.0
Storm Damage Reserve Applied To Offset Net Lost Margin Related To DSM								5.0
Storm damage reserve [Member] | SCEG
Regulatory Assets
Regulatory Liabilities	6.0			6.0				6.0
Planned major maintenance [Member]
Regulatory Assets
Regulatory Liabilities	15.0			15.0				0.0
Planned major maintenance [Member] | SCEG
Regulatory Assets
Regulatory Liabilities	15.0			15.0				0.0
Amounts Recovered through Electric Rates to offset Turbine Expense				18.4
Deferred gains on interest rate derivatives [Member]
Regulatory Assets
Regulatory Liabilities	123.0			123.0				82.0
Deferred gains on interest rate derivatives [Member] | SCEG
Regulatory Assets
Regulatory Liabilities	123.0			$ 123.0				82.0
Pension costs, electric [Member] | SCEG
Regulatory Assets
Regulatory Noncurrent Asset, Amortization Period				30
Defined Benefit Plan, Deferred Debit Attributable to Share of Regulatory Authority	63.0			$ 63.0
Franchise agreement Costs [Member]
Regulatory Assets
Regulatory Assets, Noncurrent	24.0			24.0				26.0
Franchise agreement Costs [Member] | SCEG
Regulatory Assets
Regulatory Assets, Noncurrent	24.0			24.0				26.0
Deferred Losses On Interest Rate Derivatives [Member]
Regulatory Assets
Regulatory Assets, Noncurrent	455.0			455.0				453.0
Deferred Losses On Interest Rate Derivatives [Member] | SCEG
Regulatory Assets
Regulatory Assets, Noncurrent	455.0			455.0				453.0
Deferred Pollution Control Cost [Member]
Regulatory Assets
Regulatory Assets, Noncurrent	35.0			35.0				36.0
Deferred Pollution Control Cost [Member] | SCEG
Regulatory Assets
Regulatory Assets, Noncurrent	35.0			35.0				36.0
Regulatory Clause Revenues, under-recovered [Member]
Regulatory Assets
Regulatory Assets, Noncurrent	0.0			0.0				20.0
Regulatory Clause Revenues, under-recovered [Member] | SCEG
Regulatory Assets
Regulatory Assets, Noncurrent	0.0			0.0				20.0
Planned major maintenance [Member]
Regulatory Assets
Regulatory Assets, Noncurrent	0.0			0.0				2.0
Planned major maintenance [Member] | SCEG
Regulatory Assets
Regulatory Assets, Noncurrent	0.0			$ 0.0				2.0
Asset Retirement Obligation Costs [Member]
Regulatory Assets
Regulatory Noncurrent Asset, Amortization Period				90
Regulatory Assets, Noncurrent	373.0			$ 373.0				366.0
Asset Retirement Obligation Costs [Member] | SCEG
Regulatory Assets
Regulatory Assets, Noncurrent	353.0			353.0				347.0
unrecovered plant [Member]
Regulatory Assets
Regulatory Assets, Noncurrent	131.0			131.0				137.0
unrecovered plant [Member] | SCEG
Regulatory Assets
Regulatory Assets, Noncurrent	131.0			131.0				137.0
Demand Side Management programs [Member]
Regulatory Assets
Regulatory Assets, Noncurrent	59.0			59.0				56.0
Demand Side Management programs [Member] | SCEG
Regulatory Assets
Regulatory Assets, Noncurrent	59.0			59.0				56.0
Carrying cost on nuclear construction [Member]
Regulatory Assets
Regulatory Assets, Noncurrent	13.0			13.0				9.0
Carrying cost on nuclear construction [Member] | SCEG
Regulatory Assets
Regulatory Assets, Noncurrent	13.0			13.0				9.0
Pipeline integerity management costs [Member]
Regulatory Assets
Regulatory Assets, Noncurrent	13.0			$ 13.0				9.0
Deferred Income Tax Charges [Member]
Regulatory Assets
Regulatory Noncurrent Asset, Amortization Period				70
Regulatory Assets, Noncurrent	283.0			$ 283.0				284.0
Deferred Income Tax Charges [Member] | SCEG
Regulatory Assets
Regulatory Noncurrent Asset, Amortization Period				70
Regulatory Assets, Noncurrent	277.0			$ 277.0				278.0
Environmental Restoration Costs [Member]
Regulatory Assets
MPG enviromental remediatio
Regulatory Assets, Noncurrent	39.0			$ 39.0				40.0
Environmental Restoration Costs [Member] | SCEG
Regulatory Assets
Regulatory Assets, Noncurrent	35.0			35.0				36.0
Pension Costs [Member]
Regulatory Assets
Regulatory Assets, Noncurrent	332.0			$ 332.0				350.0
Pension Costs [Member] | SCEG
Regulatory Assets
Regulatory Noncurrent Asset, Amortization Period				12					30
Regulatory Assets, Noncurrent	300.0			$ 300.0				310.0
Pension costs, gas [Member] | SCEG
Regulatory Assets
Regulatory Noncurrent Asset, Amortization Period				14
Defined Benefit Plan, Deferred Debit Attributable to Share of Regulatory Authority	14.0			$ 14.0
Other Regulatory Assets [Member]
Regulatory Assets
Regulatory Noncurrent Asset, Amortization Period				30		30
Regulatory Assets, Noncurrent	$ 41.0			$ 41.0				35.0
Other Regulatory Assets [Member] | SCEG
Regulatory Assets
Regulatory Noncurrent Asset, Amortization Period				50			50
Regulatory Assets, Noncurrent								$ 35.0