EMPLOYEE BENEFIT PLANS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension and Other Postretirement Benefit Plans
Pension Contributions	No	No
Pension Benefits
Components of Net Periodic Benefit Cost
Service cost	5.8	5.0
Interest cost	9.5	10.2
Expected return on assets	(15.5)	(16.8)
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Recognized in Net Periodic Benefit Cost, before Tax	1.0	1.0
Defined Benefit Plan, Actuarial Net (Gains) Losses	3.5	1.3
Defined Benefit Plan, Net Periodic Benefit Cost	4.3	0.7
Other Postretirement Benefits
Components of Net Periodic Benefit Cost
Service cost	1.4	1.2
Interest cost	2.9	3.1
Expected return on assets	0	0
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Recognized in Net Periodic Benefit Cost, before Tax	0.1	0.1
Defined Benefit Plan, Actuarial Net (Gains) Losses	0.6	0.1
Defined Benefit Plan, Net Periodic Benefit Cost	5.0	4.5
SCEG
Pension and Other Postretirement Benefit Plans
Pension Contributions	No	No
SCEG | Pension Benefits
Components of Net Periodic Benefit Cost
Service cost	4.6	4.0
Interest cost	8.0	8.6
Expected return on assets	13.0	14.2
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Recognized in Net Periodic Benefit Cost, before Tax	0.8	0.9
Defined Benefit Plan, Actuarial Net (Gains) Losses	(3.0)	(1.1)
Defined Benefit Plan, Net Periodic Benefit Cost	3.4	0.4
SCEG | Other Postretirement Benefits
Components of Net Periodic Benefit Cost
Service cost	1.1	1.0
Interest cost	2.3	2.4
Expected return on assets	0	0
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Recognized in Net Periodic Benefit Cost, before Tax	0.1	0.1
Defined Benefit Plan, Actuarial Net (Gains) Losses	(0.4)	(0.1)
Defined Benefit Plan, Net Periodic Benefit Cost	3.9	3.6
Pension Costs [Member] | SCEG
Components of Net Periodic Benefit Cost
Defined Benefit Plan, Deferred Debit Attributable to Share of Regulatory Authority	14				$ 63
Regulatory Noncurrent Asset, Amortization Period	12		14	30