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Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Article 5 false23true 4us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstractus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse6falsefalsefalse00falsefalsefalse7falsefalsefalse00falsefalsefalse8falsefalsefalse00falsefalsefalse9falsefalsefalse00falsefalsefalse10falsefalsefalse00falsefalsefalse11falsefalsefalse00falsefalsefalse12falsefalsefalse00falsefalsefalse13falsefalsefalse00falsefalsefalse14falsefalsefalse00falsefalsefalse15falsefalsefalse00falsefalsefalse16falsefalsefalse00falsefalsefalse17falsefalsefalse00falsefalsefalse18falsefalsefalse00falsefalsefalse19falsefalsefalse00falsefalsefalse20falsefalsefalse00falsefalsefalse21falsefalsefalse00falsefalsefalse22falsefalsefalse00falsefalsefalse23falsefalsefalse00falsefalsefalse24falsefalsefalse00falsefalsefalse25falsefalsefalse00falsefalsefalse26falsefalsefalse00falsefalsefalse27falsefalsefalse00falsefalsefalse28falsefalsefalse00falsefalsefalse29falsefalsefalse00falsefalsefalse30falsefalsefalse00falsefalsefalse31falsefalsefalse00falsefalsefalse32falsefalsefalse00falsefalsefalse33falsefalsefalse00falsefalsefalse34falsefalsefalse00falsefalsefalse35falsefalsefalse00falsefalsefalse36falsefalsefalse00falsefalsefalse37falsefalsefalse00falsefalsefalse38falsefalsefalse00falsefalsefalse39falsefalsefalse00falsefalsefalse40falsefalsefalse00falsefalsefalse41falsefalsefalse00falsefalsefalse42falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse04false 5us-gaap_Revenuesus-gaap_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-22000000-22000000falsefalsefalse26truefalsefalse-20000000-20000000falsefalsefalse27truefalsefalse-46000000-46000000falsefalsefalse28truefalsefalse-43000000-43000000falsefalsefalse29falsefalsefalse00falsefalsefalse30truefalsefalse-95000000-95000000falsefalsefalse31truefalsefalse-109000000-109000000falsefalsefalse32truefalsefalse-181000000-181000000falsefalsefalse33truefalsefalse-222000000-222000000falsefalsefalse34falsefalsefalse00falsefalsefalse35truefalsefalse3800000038000000falsefalsefalse36truefalsefalse3500000035000000falsefalsefalse37truefalsefalse7300000073000000falsefalsefalse38truefalsefalse7300000073000000falsefalsefalse39falsefalsefalse00falsefalsefalse40falsefalsefalse00falsefalsefalse41falsefalsefalse00falsefalsefalse42falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Article 5 false25false 5us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse297000000297000000[1],[2]falsefalsefalse2truefalsefalse623000000623000000[1]falsefalsefalse3truefalsefalse378000000378000000falsefalsefalse4truefalsefalse991000000991000000[1]falsefalsefalse5falsefalsefalse00falsefalsefalse6truefalsefalse296000000296000000[1],[2]falsefalsefalse7truefalsefalse596000000596000000[1]falsefalsefalse8truefalsefalse391000000391000000[1],[3]falsefalsefalse9truefalsefalse964000000964000000[1]falsefalsefalse10falsefalsefalse00falsefalsefalse11truefalsefalse268000000268000000[1],[2]falsefalsefalse12truefalsefalse549000000549000000[1]falsefalsefalse13truefalsefalse334000000334000000[1],[3]falsefalsefalse14truefalsefalse888000000888000000[1]falsefalsefalse15falsefalsefalse00falsefalsefalse16falsefalsefalse00falsefalsefalse17falsefalsefalse00falsefalsefalse18falsefalsefalse00falsefalsefalse19falsefalsefalse00falsefalsefalse20truefalsefalse2800000028000000[1],[2]falsefalsefalse21truefalsefalse4700000047000000[1]falsefalsefalse22truefalsefalse5700000057000000[1],[3]falsefalsefalse23truefalsefalse7600000076000000[1]falsefalsefalse24falsefalsefalse00falsefalsefalse25truefalsefalse-3000000-3000000[1],[2]falsefalsefalse26truefalsefalse00[1]falsefalsefalse27truefalsefalse-1000000-1000000[1],[3]falsefalsefalse28truefalsefalse-1000000-1000000[1]falsefalsefalse29falsefalsefalse00falsefalsefalse30truefalsefalse00[1],[2]falsefalsefalse31truefalsefalse00[1]falsefalsefalse32truefalsefalse00[1],[3]falsefalsefalse33truefalsefalse00[1]falsefalsefalse34falsefalsefalse00falsefalsefalse35truefalsefalse40000004000000[1],[2]falsefalsefalse36truefalsefalse2700000027000000[1]falsefalsefalse37truefalsefalse-12000000-12000000[1],[3]falsefalsefalse38truefalsefalse2800000028000000[1]falsefalsefalse39falsefalsefalse00falsefalsefalse40falsefalsefalse00falsefalsefalse41falsefalsefalse00falsefalsefalse42falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryNet income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e1377-109256 false26false 5us-gaap_Assetsus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse6396100000063961000000falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse6396100000063961000000falsefalsefalse4falsefalsefalse00falsefalsefalse5truefalsefalse6314900000063149000000falsefalsefalse6truefalsefalse6319400000063194000000falsefalsefalse7falsefalsefalse00falsefalsefalse8truefalsefalse6319400000063194000000falsefalsefalse9falsefalsefalse00falsefalsefalse10truefalsefalse6225100000062251000000falsefalsefalse11truefalsefalse5917700000059177000000falsefalsefalse12falsefalsefalse00falsefalsefalse13truefalsefalse5917700000059177000000falsefalsefalse14falsefalsefalse00falsefalsefalse15truefalsefalse5860000000058600000000falsefalsefalse16falsefalsefalse00falsefalsefalse17falsefalsefalse00falsefalsefalse18falsefalsefalse00falsefalsefalse19falsefalsefalse00falsefalsefalse20truefalsefalse41390000004139000000falsefalsefalse21falsefalsefalse00falsefalsefalse22truefalsefalse41390000004139000000falsefalsefalse23falsefalsefalse00falsefalsefalse24truefalsefalse37800000003780000000falsefalsefalse25truefalsefalse-297000000-297000000falsefalsefalse26falsefalsefalse00falsefalsefalse27truefalsefalse-297000000-297000000falsefalsefalse28falsefalsefalse00falsefalsefalse29truefalsefalse-218000000-218000000falsefalsefalse30truefalsefalse-122000000-122000000falsefalsefalse31falsefalsefalse00falsefalsefalse32truefalsefalse-122000000-122000000falsefalsefalse33falsefalsefalse00falsefalsefalse34truefalsefalse-129000000-129000000falsefalsefalse35truefalsefalse10640000001064000000falsefalsefalse36falsefalsefalse00falsefalsefalse37truefalsefalse10640000001064000000falsefalsefalse38falsefalsefalse00falsefalsefalse39truefalsefalse11160000001116000000falsefalsefalse40falsefalsefalse00falsefalsefalse41falsefalsefalse00falsefalsefalse42falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetarySum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.18) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 12 -Article 7 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 false27false 5so_PreTaxChargeToIncomeso_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse6falsefalsefalse00falsefalsefalse7falsefalsefalse00falsefalsefalse8falsefalsefalse00falsefalsefalse9falsefalsefalse00falsefalsefalse10falsefalsefalse00falsefalsefalse11falsefalsefalse00falsefalsefalse12falsefalsefalse00falsefalsefalse13falsefalsefalse00falsefalsefalse14falsefalsefalse00falsefalsefalse15falsefalsefalse00falsefalsefalse16falsefalsefalse00falsefalsefalse17falsefalsefalse00falsefalsefalse18falsefalsefalse00falsefalsefalse19falsefalsefalse00falsefalsefalse20falsefalsefalse00falsefalsefalse21falsefalsefalse00falsefalsefalse22falsefalsefalse00falsefalsefalse23falsefalsefalse00falsefalsefalse24falsefalsefalse00falsefalsefalse25falsefalsefalse00falsefalsefalse26falsefalsefalse00falsefalsefalse27falsefalsefalse00falsefalsefalse28falsefalsefalse00falsefalsefalse29falsefalsefalse00falsefalsefalse30falsefalsefalse00falsefalsefalse31falsefalsefalse00falsefalsefalse32falsefalsefalse00falsefalsefalse33falsefalsefalse00falsefalsefalse34falsefalsefalse00falsefalsefalse35falsefalsefalse00falsefalsefalse36falsefalsefalse00falsefalsefalse37falsefalsefalse00falsefalsefalse38falsefalsefalse00falsefalsefalse39falsefalsefalse00falsefalsefalse40truefalsefalse450000000450000000falsefalsefalse41truefalsefalse990000000990000000falsefalsefalse42truefalsefalse540000000540000000falsefalsefalsexbrli:monetaryItemTypemonetaryPre-Tax Charge To IncomeNo definition available.false28false 5so_AfterTaxChargeToIncomeso_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse1600000016000000USD$falsetruefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse6falsefalsefalse00falsefalsefalse7falsefalsefalse00falsefalsefalse8falsefalsefalse00falsefalsefalse9falsefalsefalse00falsefalsefalse10falsefalsefalse00falsefalsefalse11falsefalsefalse00falsefalsefalse12falsefalsefalse00falsefalsefalse13falsefalsefalse00falsefalsefalse14falsefalsefalse00falsefalsefalse15falsefalsefalse00falsefalsefalse16falsefalsefalse00falsefalsefalse17falsefalsefalse00falsefalsefalse18falsefalsefalse00falsefalsefalse19falsefalsefalse00falsefalsefalse20falsefalsefalse00falsefalsefalse21falsefalsefalse00falsefalsefalse22falsefalsefalse00falsefalsefalse23falsefalsefalse00falsefalsefalse24falsefalsefalse00falsefalsefalse25falsefalsefalse00falsefalsefalse26falsefalsefalse00falsefalsefalse27falsefalsefalse00falsefalsefalse28falsefalsefalse00falsefalsefalse29falsefalsefalse00falsefalsefalse30falsefalsefalse00falsefalsefalse31falsefalsefalse00falsefalsefalse32falsefalsefalse00falsefalsefalse33falsefalsefalse00falsefalsefalse34falsefalsefalse00falsefalsefalse35falsefalsefalse00falsefalsefalse36falsefalsefalse00falsefalsefalse37falsefalsefalse00falsefalsefalse38falsefalsefalse00falsefalsefalse39falsefalsefalse00falsefalsefalse40truefalsefalse277900000277900000USD$falsetruefalse41truefalsefalse611300000611300000USD$falsetruefalse42truefalsefalse333500000333500000USD$falsetruefalsexbrli:monetaryItemTypemonetaryAfter Tax Charge To IncomeNo definition available.false21After dividends on preferred and preference stock of subsidiaries.2Segment net income (loss) for the three months ended June 30, 2013 includes a $450 million pre-tax charge ($277.9 million after tax) for an estimated probable loss on the Kemper IGCC. See Note (B) under "Integrated Coal Gasification Combined Cycle – Kemper IGCC Cost Estimate" herein for additional information.3Segment net income (loss) for the six months ended June 30, 2013 includes a $990 million pre-tax charge ($611.3 million after tax) for estimated probable losses on the Kemper IGCC. See Note (B) under "Integrated Coal Gasification Combined Cycle – Kemper IGCC Cost Estimate" herein for additional information.falseSegment and Related Information - Financial Data for Business Segments (Details) (USD $)NoRoundingUnKnownUnKnownUnKnowntruefalsefalseSheethttp://southerncompany.com/role/SegmentAndRelatedInformationFinancialDataForBusinessSegmentsDetails428