v3.10.0.1

REGULATORY ASSETS AND LIABILITIES (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Mar. 31, 2019	Dec. 31, 2017
Regulatory Assets, Noncurrent	$ 4,380.0		$ 5,580.0
Regulatory Liability, Noncurrent	2,789.0		3,059.0
Asset Retirement Obligation Costs [Member]
Regulatory Liability, Noncurrent	779.0		757.0
Deferred Income Tax Charge [Member]
Regulatory Liability, Noncurrent	814.0		1,076.0
Deferred gains on interest rate derivatives [Member]
Regulatory Liability, Noncurrent	77.0		131.0
Other Regulatory Liability [Member]
Regulatory Liability, Noncurrent	21.0		0.0
Unrecovered nuclear project costs post impairment [Member]
Regulatory Assets, Noncurrent	2,768.0
Demand Side Management programs [Member]
Regulatory Assets, Noncurrent	65.0		59.0
Pipeline integrity management costs [Member]
Regulatory Assets, Noncurrent	73.0		51.0
Storm Costs [Member]
Regulatory Assets, Noncurrent	35.0		24.0
Deferred transmission operating costs [Member] [Domain]
Regulatory Assets, Noncurrent	$ 15.0		0.0
Asset Retirement Obligation Costs [Member]
Regulatory Asset, Amortization Period	106 years
Regulatory Assets, Noncurrent	$ 406.0		434.0
Pension Costs [Member]
Defined Benefit Plan, Deferred Debit Attributable to Share of Regulatory Authority	1.0
Regulatory Assets, Noncurrent	302.0		305.0
Deferred Losses On Interest Rate Derivatives [Member]
Regulatory Assets, Noncurrent	448.0		456.0
Canadys Refined Coal [Member]
Regulatory Assets, Noncurrent	93.0		105.0
Environmental Restoration Costs [Member]
Regulatory Assets, Noncurrent	$ 27.0		30.0
Other Regulatory Assets [Member]
Regulatory Asset Recovery Assessments	2047
Regulatory Assets, Noncurrent	$ 148.0		140.0
Summer Station Unit 2 and Unit 3 [Domain] | Settlement Proceeds [Member]
Regulatory Liability, Noncurrent	1,098.0		1,095.0
SCE&G
Regulatory Assets, Noncurrent	4,256.0		5,476.0
Regulatory Liability, Noncurrent	2,380.0		2,667.0
SCE&G | Settlement Proceeds [Member]
Regulatory Liability, Noncurrent	1,098.0		1,095.0
SCE&G | Asset Retirement Obligation Costs [Member]
Regulatory Liability, Noncurrent	541.0		527.0
SCE&G | Deferred Income Tax Charge [Member]
Regulatory Liability, Noncurrent	659.0		914.0
SCE&G | Deferred gains on interest rate derivatives [Member]
Regulatory Liability, Noncurrent	77.0		131.0
SCE&G | Other Regulatory Liability [Member]
Regulatory Liability, Noncurrent	5.0		0.0
SCE&G | Unrecovered nuclear project costs post impairment [Member]
Regulatory Assets, Noncurrent	2,768.0		3,976.0
SCE&G | Demand Side Management programs [Member]
Regulatory Assets, Noncurrent	65.0		59.0
SCE&G | Pipeline integrity management costs [Member]
Regulatory Assets, Noncurrent	9.0		8.0
Pipeline integrity management costs, annual amortization amount	3.2	$ 1.9
SCE&G | Storm Costs [Member]
Regulatory Assets, Noncurrent	35.0		24.0
SCE&G | Deferred transmission operating costs [Member] [Domain]
Regulatory Assets, Noncurrent	15.0		0.0
SCE&G | Asset Retirement Obligation Costs [Member]
Regulatory Assets, Noncurrent	380.0		410.0
SCE&G | Pension Costs [Member]
Defined Benefit Plan, Deferred Debit Attributable to Share of Regulatory Authority	2.0
Regulatory Assets, Noncurrent	272.0		273.0
SCE&G | Deferred Losses On Interest Rate Derivatives [Member]
Regulatory Assets, Noncurrent	448.0		456.0
SCE&G | Canadys Refined Coal [Member]
Regulatory Assets, Noncurrent	93.0		105.0
SCE&G | Environmental Restoration Costs [Member]
Regulatory Assets, Noncurrent	24.0		25.0
SCE&G | Other Regulatory Assets [Member]
Regulatory Assets, Noncurrent			$ 140.0
PSNC Energy [Member]
Pipeline integrity management costs, amount recovering beginning November 2016	4.1
Pipeline integrity management costs, amount deferred pending future approval of rate recovery	$ 51.3

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Amortization period for the recovery of regulatory asset, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Describes the continual or periodic assessment of the probability of future recovery of regulatory assets.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 340
-Section 40
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Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer.

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The amount for the individual regulatory noncurrent liability as itemized in a table of regulatory noncurrent liabilities as of the end of the period.

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