INCOME TAXES	3 Months Ended
INCOME TAXES	Mar. 31, 2018
income tax [Line Items]
Income Tax Disclosure [Text Block]	6. INCOME TAXES The Company files consolidated federal income tax returns which include Consolidated SCE&G, and the Company and its subsidiaries file various applicable state and local income tax returns. The Company’s federal returns through 2007 are closed. In addition, federal returns for 2008 and 2009 are closed except to the extent of the examination of amended return claims discussed below. The IRS is also currently examining SCANA's federal returns for years 2010 through 2016 as a result of those claims. With few exceptions, the Company, including Consolidated SCE&G, is no longer subject to state and local income tax examinations by tax authorities for years before 2010. During 2013 and 2014, the Company amended certain of its income tax returns for 2008 through 2012 to claim additional tax-defined research and experimentation deductions (under IRC Section 174) and credits (under IRC Section 41) and to reflect related impacts on other items such as domestic production activities deductions (under IRC Section 199). The Company also made similar claims in filing its original 2013 and 2014 returns in 2014 and 2015, respectively. In 2016 and 2017, the Company claimed significant research and experimentation deductions and credits (offset by reductions in its domestic production activities deductions), related to the design and construction activities of the Nuclear Project, in its 2015 and 2016 income tax returns. The Company expects to claim similar deductions and credits in its 2017 tax return when it is filed in 2018. These claims followed the issuance of final IRS regulations in 2014 regarding such treatment with respect to expenditures related to the design and construction of pilot models. The IRS examined the claims in the amended returns, and as the examination progressed without resolution, the Company and Consolidated SCE&G evaluated and recorded adjustments to unrecognized tax benefits; however, none of these changes materially affected the Company's and Consolidated SCE&G's effective tax rate. In October 2016, the examination of the amended tax returns progressed to the IRS Office of Appeals. In addition, the IRS has begun an examination of SCANA's 2013 through 2016 income tax returns, and it is expected that the IRS will also examine later returns. These IRC Section 174 income tax deductions and IRC Section 41 credits were considered to be uncertain tax positions, and under relevant accounting guidance, estimates of the amounts of related tax benefits which may not be sustained upon examination by the taxing authorities were recorded as unrecognized tax benefits in the financial statements. Following the abandonment of the Nuclear Project, the Company and Consolidated SCE&G anticipate that an abandonment loss deduction under IRC Section 165 will be claimed on the 2017 tax return. As such, certain of the IRC Section 174 deductions, to the extent they are denied, would instead be deductible in 2017 under IRC Section 165. The abandonment loss deduction is also considered an uncertain tax position; however, under relevant accounting guidance, no estimated unrecognized tax benefits were recorded as of March 31, 2018. The remaining unrecognized tax benefits include the impact of the IRC Section 174 deductions on domestic production activities deductions, credits, and certain unrecognized state tax benefits. As of March 31, 2018, the Company and Consolidated SCE&G have recorded an unrecognized tax benefit of $98 million ($19 million net of the impact of state deductions on federal returns, net of NOL and credit carryforwards, and net of receivables related to the uncertain tax positions). If recognized, $98 million of the tax benefit would affect the Company’s and Consolidated SCE&G's effective tax rates. These unrecognized tax benefits are not expected to increase significantly within the next 12 months. It is also reasonably possible that these unrecognized tax benefits may decrease by $11 million within the next 12 months. No other material changes in the status of the Company’s or Consolidated SCE&G's tax positions have occurred through March 31, 2018 (see Note 10). In connection with the research and experimentation deduction and credit claims reflected on the 2015 and 2016 income tax returns and similar claims made in determining taxable income for 2017, and under the terms of an SCPSC order, the Company and Consolidated SCE&G recorded regulatory assets for estimated foregone domestic production activities deductions, offset by estimated tax credits, with the expectation that these deferred costs and related interest thereon would be recoverable through customer rates in future years (see Note 2). However, an impairment loss with respect to such deferred regulatory asset was recorded in 2017. Also under the terms of an SCPSC order, estimated interest expense accrued with respect to the unrecognized tax benefits related to the research and experimentation deductions in the 2015 and 2016 income tax returns was deferred as a regulatory asset through December 31, 2017 and was expected to be recoverable through customer rates in future years. An impairment loss with respect to these deferred amounts was also recorded as of December 31, 2017 (see Note 10). Otherwise, the Company and Consolidated SCE&G recognize interest accrued related to unrecognized tax benefits within interest expense or interest income and recognize tax penalties within other expenses. Related to the unrecognized tax benefits noted above, the Company and Consolidated SCE&G accrued interest expense of $4.5 million and interest income of $0.7 million during 2018. Amounts recorded for such interest income and interest expense were mostly deferred within regulatory assets during 2017 and were subsequently included within the impairment loss recorded by the Company and Consolidated SCE&G in 2017. Penalties were not material in either period presented. In December of 2017, the Tax Act was enacted to lower the federal statutory tax rate from 35% to 21%. The rate change resulted in the remeasurement of all federal deferred income tax assets and liabilities to reflect a 21% federal statutory tax rate as of December 31, 2017. Due to the regulated nature of the Company’s and Consolidated SCE&G’s operations, the effect of this remeasurement is primarily reflected in deferred income tax balances within regulatory liabilities. As of March 31, 2018, the amortization of amounts arising from remeasurement have not affected the Company’s or Consolidated SCE&G’s effective tax rate due to such amortizations being deferred until such time as regulators determine how the benefits of such excess deferred tax amounts will be realized by customers. Upon the filing of the Company’s 2017 consolidated income tax return, adjustments to deferred income taxes may be recorded; however, these adjustments are not expected to have a material impact on the Company’s financial position, results of operations, or cash flows. The State of North Carolina lowered its corporate income tax rate to 3.0% in 2017 and 2.5% effective January 1, 2019. In connection with these changes in tax rates, related state deferred tax amounts were remeasured, with the change in their balances being credited to a regulatory liability. The changes in income tax rates did not and are not expected to have a material impact on the Company’s financial position, results of operations or cash flows.
SCEG
income tax [Line Items]
Income Tax Disclosure [Text Block]	6. INCOME TAXES The Company files consolidated federal income tax returns which include Consolidated SCE&G, and the Company and its subsidiaries file various applicable state and local income tax returns. The Company’s federal returns through 2007 are closed. In addition, federal returns for 2008 and 2009 are closed except to the extent of the examination of amended return claims discussed below. The IRS is also currently examining SCANA's federal returns for years 2010 through 2016 as a result of those claims. With few exceptions, the Company, including Consolidated SCE&G, is no longer subject to state and local income tax examinations by tax authorities for years before 2010. During 2013 and 2014, the Company amended certain of its income tax returns for 2008 through 2012 to claim additional tax-defined research and experimentation deductions (under IRC Section 174) and credits (under IRC Section 41) and to reflect related impacts on other items such as domestic production activities deductions (under IRC Section 199). The Company also made similar claims in filing its original 2013 and 2014 returns in 2014 and 2015, respectively. In 2016 and 2017, the Company claimed significant research and experimentation deductions and credits (offset by reductions in its domestic production activities deductions), related to the design and construction activities of the Nuclear Project, in its 2015 and 2016 income tax returns. The Company expects to claim similar deductions and credits in its 2017 tax return when it is filed in 2018. These claims followed the issuance of final IRS regulations in 2014 regarding such treatment with respect to expenditures related to the design and construction of pilot models. The IRS examined the claims in the amended returns, and as the examination progressed without resolution, the Company and Consolidated SCE&G evaluated and recorded adjustments to unrecognized tax benefits; however, none of these changes materially affected the Company's and Consolidated SCE&G's effective tax rate. In October 2016, the examination of the amended tax returns progressed to the IRS Office of Appeals. In addition, the IRS has begun an examination of SCANA's 2013 through 2016 income tax returns, and it is expected that the IRS will also examine later returns. These IRC Section 174 income tax deductions and IRC Section 41 credits were considered to be uncertain tax positions, and under relevant accounting guidance, estimates of the amounts of related tax benefits which may not be sustained upon examination by the taxing authorities were recorded as unrecognized tax benefits in the financial statements. Following the abandonment of the Nuclear Project, the Company and Consolidated SCE&G anticipate that an abandonment loss deduction under IRC Section 165 will be claimed on the 2017 tax return. As such, certain of the IRC Section 174 deductions, to the extent they are denied, would instead be deductible in 2017 under IRC Section 165. The abandonment loss deduction is also considered an uncertain tax position; however, under relevant accounting guidance, no estimated unrecognized tax benefits were recorded as of March 31, 2018. The remaining unrecognized tax benefits include the impact of the IRC Section 174 deductions on domestic production activities deductions, credits, and certain unrecognized state tax benefits. As of March 31, 2018, the Company and Consolidated SCE&G have recorded an unrecognized tax benefit of $98 million ($19 million net of the impact of state deductions on federal returns, net of NOL and credit carryforwards, and net of receivables related to the uncertain tax positions). If recognized, $98 million of the tax benefit would affect the Company’s and Consolidated SCE&G's effective tax rates. These unrecognized tax benefits are not expected to increase significantly within the next 12 months. It is also reasonably possible that these unrecognized tax benefits may decrease by $11 million within the next 12 months. No other material changes in the status of the Company’s or Consolidated SCE&G's tax positions have occurred through March 31, 2018 (see Note 10). In connection with the research and experimentation deduction and credit claims reflected on the 2015 and 2016 income tax returns and similar claims made in determining taxable income for 2017, and under the terms of an SCPSC order, the Company and Consolidated SCE&G recorded regulatory assets for estimated foregone domestic production activities deductions, offset by estimated tax credits, with the expectation that these deferred costs and related interest thereon would be recoverable through customer rates in future years (see Note 2). However, an impairment loss with respect to such deferred regulatory asset was recorded in 2017. Also under the terms of an SCPSC order, estimated interest expense accrued with respect to the unrecognized tax benefits related to the research and experimentation deductions in the 2015 and 2016 income tax returns was deferred as a regulatory asset through December 31, 2017 and was expected to be recoverable through customer rates in future years. An impairment loss with respect to these deferred amounts was also recorded as of December 31, 2017 (see Note 10). Otherwise, the Company and Consolidated SCE&G recognize interest accrued related to unrecognized tax benefits within interest expense or interest income and recognize tax penalties within other expenses. Related to the unrecognized tax benefits noted above, the Company and Consolidated SCE&G accrued interest expense of $4.5 million and interest income of $0.7 million during 2018. Amounts recorded for such interest income and interest expense were mostly deferred within regulatory assets during 2017 and were subsequently included within the impairment loss recorded by the Company and Consolidated SCE&G in 2017. Penalties were not material in either period presented. In December of 2017, the Tax Act was enacted to lower the federal statutory tax rate from 35% to 21%. The rate change resulted in the remeasurement of all federal deferred income tax assets and liabilities to reflect a 21% federal statutory tax rate as of December 31, 2017. Due to the regulated nature of the Company’s and Consolidated SCE&G’s operations, the effect of this remeasurement is primarily reflected in deferred income tax balances within regulatory liabilities. As of March 31, 2018, the amortization of amounts arising from remeasurement have not affected the Company’s or Consolidated SCE&G’s effective tax rate due to such amortizations being deferred until such time as regulators determine how the benefits of such excess deferred tax amounts will be realized by customers. Upon the filing of the Company’s 2017 consolidated income tax return, adjustments to deferred income taxes may be recorded; however, these adjustments are not expected to have a material impact on the Company’s financial position, results of operations, or cash flows. The State of North Carolina lowered its corporate income tax rate to 3.0% in 2017 and 2.5% effective January 1, 2019. In connection with these changes in tax rates, related state deferred tax amounts were remeasured, with the change in their balances being credited to a regulatory liability. The changes in income tax rates did not and are not expected to have a material impact on the Company’s financial position, results of operations or cash flows.