REGULATORY ASSETS AND LIABILITIES(Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2013
Regulatory Assets, Noncurrent	$ 2,130.0	$ 1,937.0
Regulatory Liability, Noncurrent	930.0	855.0
Asset Retirement Obligation Costs [Member]
Regulatory Liability, Noncurrent	755.0	732.0
Deferred gains on interest rate derivatives [Member]
Regulatory Liability, Noncurrent	151.0	96.0
Other Regulatory Liability [Member]
Regulatory Liability, Noncurrent	24.0	27.0
Demand Side Management programs [Member]
Regulatory Assets, Noncurrent	59.0	61.0
Pipeline integrity management costs [Member]
Regulatory Assets, Noncurrent	33.0	19.0
carrying cost on nuclear [Member]
Regulatory Assets, Noncurrent	32.0	18.0
Storm Costs [Member]
Regulatory Assets, Noncurrent	20.0	0.0
Deferred costs uncertain tax position [Member]
Regulatory Assets, Noncurrent	$ 15.0	0.0
Deferred Income Tax Charge [Member]
Regulatory Asset, Amortization Period	85 years
Regulatory Assets, Noncurrent	$ 316.0	298.0
Asset Retirement Obligation Costs [Member]
Regulatory Asset, Amortization Period	110 years
Regulatory Assets, Noncurrent	$ 425.0	405.0
Pension Costs [Member]
Regulatory Assets, Noncurrent	342.0	325.0
Deferred Losses On Interest Rate Derivatives [Member]
Regulatory Assets, Noncurrent	620.0	535.0
Canadys Refined Coal [Member]
Regulatory Assets, Noncurrent	117.0	127.0
Environmental Restoration Costs [Member]
Regulatory Assets, Noncurrent	32.0	42.0
Other Regulatory Assets [Member]
Regulatory Assets, Noncurrent	119.0	107.0
SCE&G
Regulatory Assets, Noncurrent	2,030.0	1,857.0
Regulatory Liability, Noncurrent	695.0	635.0
SCE&G | Asset Retirement Obligation Costs [Member]
Regulatory Liability, Noncurrent	529.0	519.0
SCE&G | Deferred gains on interest rate derivatives [Member]
Regulatory Liability, Noncurrent	151.0	96.0
SCE&G | Other Regulatory Liability [Member]
Regulatory Liability, Noncurrent	$ 15.0	20.0
SCE&G | Demand Side Management programs [Member]
Regulatory Asset, Amortization Period	5 years
Regulatory Assets, Noncurrent	$ 59.0	61.0
SCE&G | Pipeline integrity management costs [Member]
Regulatory Assets, Noncurrent	6.0	4.0
Pipeline integrity management costs, annual amortization amount	$ 1.9
SCE&G | carrying cost on nuclear [Member]
Regulatory Asset, Amortization Period	10 years
Regulatory Assets, Noncurrent	$ 32.0	18.0
SCE&G | Storm Costs [Member]
Regulatory Assets, Noncurrent	20.0	0.0
SCE&G | Deferred costs uncertain tax position [Member]
Regulatory Assets, Noncurrent	15.0	0.0
SCE&G | Deferred Income Tax Charge [Member]
Regulatory Assets, Noncurrent	307.0	291.0
SCE&G | Asset Retirement Obligation Costs [Member]
Regulatory Assets, Noncurrent	$ 403.0	384.0
SCE&G | Pension Costs [Member]
Regulatory Asset, Amortization Period	11 years
Defined Benefit Plan, Deferred Debit Attributable to Share of Regulatory Authority	$ 14.0		$ 63.0
Regulatory Assets, Noncurrent	309.0	295.0
SCE&G | Deferred Losses On Interest Rate Derivatives [Member]
Regulatory Assets, Noncurrent	620.0	535.0
SCE&G | Canadys Refined Coal [Member]
Regulatory Assets, Noncurrent	$ 117.0	127.0
SCE&G | Environmental Restoration Costs [Member]
MPG environmental remediation	18
Regulatory Assets, Noncurrent	$ 26.0	35.0
SCE&G | Other Regulatory Assets [Member]
Regulatory Assets, Noncurrent	116.0	$ 107.0
PSNC Energy [Member]
Pipeline integrity management costs, amount recovering beginning November 2016	20.3
Pipeline integrity management costs, amount deferred pending future approval of rate recovery	$ 7.0
PSNC Energy [Member] | Pipeline integrity management costs [Member]
Regulatory Asset, Amortization Period	5 years