RATE AND OTHER REGULATORY MATTERS (Details) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2013
SCEG
Rate Matters [Line Items]
Capacity of renewable energy facilities by 2020	84.5
SCPSC Order, Recovery Of Projected DER Program Costs	$ 16.5
SCPSC Order for Increase of Total Fuel Cost Component of Retail Electric Rates to produce a projected under recovery	61.0
SCPSC Order, Approx Annual pension rider decrease amount	11.9
Carrying costs on deferred income tax assets	4.3	$ 3.1
SCPSC Order, Annual DSM Program Rate Rider Recovery Amount	37.0
PSNC Energy
Rate Matters [Line Items]
Pipeline integrity mgmt annual revenue requirement approved by NCUC	$ 1.9
Deferred Income Tax Charges [Member]
Rate Matters [Line Items]
Regulatory Noncurrent Asset Amortization Period	85 years
Asset Retirement Obligation Costs [Member]
Rate Matters [Line Items]
Regulatory Noncurrent Asset Amortization Period	110 years
Environmental Restoration Costs [Member]
Rate Matters [Line Items]
MPG environmental remediation	18
Pension costs, electric [Member] | SCEG
Rate Matters [Line Items]
Regulatory Noncurrent Asset Amortization Period			30 years
Defined Benefit Plan, Deferred Debit Attributable to Share of Regulatory Authority	$ 63.0
Pension costs, gas [Member] | SCEG
Rate Matters [Line Items]
Regulatory Noncurrent Asset Amortization Period			14 years
Defined Benefit Plan, Deferred Debit Attributable to Share of Regulatory Authority	$ 14.0
Pension Costs [Member] | SCEG
Rate Matters [Line Items]
Regulatory Noncurrent Asset Amortization Period	11 years