EMPLOYEE BENEFIT PLANS EMPLOYEE BENEFIT PLANS (Details 4) $ in Millions	Dec. 31, 2016 USD ($)
Pension Plan, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	$ 63.1
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	65.1
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	64.5
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	64.7
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	67.1
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	324.4
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	12.9
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	13.7
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	14.5
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	15.3
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	15.9
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	86.0
SCE&G | Pension Plan, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	63.1
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	65.1
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	64.5
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	64.7
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	67.1
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	324.4
SCE&G | Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	10.6
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	11.2
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	11.9
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	12.5
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	13.1
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	$ 70.5