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It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 falsefalseCash and cash equivalents6false0us-gaap_RestrictedCashAndInvestmentsCurrentus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse6800000068000000falsefalsefalsefalsefalse2truefalsefalse4300000043000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe current cash, cash equivalents and investments that are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against short-term borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. Includes current cash equivalents and investments that are similarly restricted as to withdrawal, usage or disposal.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 falsefalseRestricted cash and cash equivalents7true0us-gaap_ReceivablesNetCurrentAbstractus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseReceivables --8false0us-gaap_AccountsReceivableGrossCurrentus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse11400000001140000000falsefalsefalsefalsefalse2truefalsefalse953000000953000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAmounts due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer) for goods or services (including trade receivables) that have been delivered or sold in the normal course of business.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 3 -Subparagraph a, b -Article 5 falsefalseCustomer accounts receivable9false0so_UnbilledRevenuesCurrentsofalsedebitinstantCarrying amount at the balance sheet date of revenues which have been earned but not yet billed.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse420000000420000000falsefalsefalsefalsefalse2truefalsefalse394000000394000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying amount at the balance sheet date of revenues which have been earned but not yet billed.No authoritative reference available.falsefalseUnbilled revenues10false0so_UnderRecoveredRegulatoryClauseRevenuessofalsedebitinstantCarrying 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available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-25000000-25000000falsefalsefalsefalsefalse2truefalsefalse-25000000-25000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryA valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 4 -Article 5 falsefalseAccumulated provision for uncollectible accounts13false0us-gaap_EnergyRelatedInventoryOtherFossilFuelus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse13080000001308000000falsefalsefalsefalsefalse2truefalsefalse14470000001447000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying amount as of the balance sheet date of other types of fuel derived from living matter of a previous geologic time, not otherwise itemized.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 6 -Subparagraph a -Article 5 falsefalseFossil fuel stock, at average cost14false0us-gaap_OtherInventorySuppliesus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse827000000827000000falsefalsefalsefalsefalse2truefalsefalse794000000794000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying amount as of the balance sheet date of products used directly or indirectly in the manufacturing or production process, which may or may not become part of the final product. May also include items used in the storage, presentation or transportation of physical goods.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 6 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 4 -Paragraph 3 falsefalseMaterials and supplies, at average cost15false0so_VacationPaysofalsedebitinstantCarrying amount at the balance sheet date of the regulatory asset related to vacation pay to employees.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse151000000151000000falsefalsefalsefalsefalse2truefalsefalse145000000145000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying amount at the balance sheet date of the regulatory asset related to vacation pay to employees.No authoritative reference available.falsefalseVacation pay16false0us-gaap_PrepaidExpenseCurrentus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse784000000784000000falsefalsefalsefalsefalse2truefalsefalse508000000508000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetarySum of the amounts paid in advance for capitalized costs that will be expensed with the passage of time or the occurrence of a triggering event, and will be charged against earnings within one year or the normal operating cycle, if longer.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 4 falsefalsePrepaid expenses17false0so_OtherRegulatoryAssetsCurrentsofalsedebitinstantCarrying amount of other regulatory assets (not elsewhere included) as of the balance sheet date of capitalized costs of...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse210000000210000000falsefalsefalsefalsefalse2truefalsefalse167000000167000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying amount of other regulatory assets (not elsewhere included) as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer. Such costs are capitalized if they meet both of the following criteria: a. It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b. Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs. 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Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 truefalseOther current assets19false0us-gaap_AssetsCurrentus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse58830000005883000000falsefalsefalsefalsefalse2truefalsefalse58730000005873000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetarySum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). 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 SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 9 -Article 5 truefalseTotal current assets20true0us-gaap_PropertyPlantAndEquipmentNetAbstractus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseProperty, Plant, and Equipment:21false0us-gaap_PropertyPlantAndEquipmentGrossus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse5673100000056731000000falsefalsefalsefalsefalse2truefalsefalse5358800000053588000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying amount at the balance sheet date for long-lived physical assets used in the normal conduct of business and not intended for resale. This can include land, physical structures, machinery, vehicles, furniture, computer equipment, construction in progress, and similar items. Amount does not include depreciation.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 falsefalseIn service22false0us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipmentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse2017400000020174000000falsefalsefalsefalsefalse2truefalsefalse1912100000019121000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 -Subparagraph c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 14 -Article 5 truefalseLess accumulated depreciation23false0so_PlantInServiceNetOfDepreciationsofalsedebitinstantCarrying amount at the balance sheet date for long-lived physical assets used in the normal conduct of business and not...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse3655700000036557000000falsefalsefalsefalsefalse2truefalsefalse3446700000034467000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying amount at the balance sheet date for long-lived physical assets used in the normal conduct of business and not intended for resale, less depreciation.No authoritative reference available.falsefalsePlant in service, net of depreciation24false0so_NuclearFuelAtAmortizedCostsofalsedebitinstantThe carrying amount as of the balance sheet of nuclear fuel held as property plant and equipment. This amount is net of...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse670000000670000000falsefalsefalsefalsefalse2truefalsefalse593000000593000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe carrying amount as of the balance sheet of nuclear fuel held as property plant and equipment. This amount is net of amortization based on the energy produced over the life of the fuel.No authoritative reference available.falsefalseNuclear fuel, at amortized cost25false0us-gaap_ConstructionInProgressGrossus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse47750000004775000000falsefalsefalsefalsefalse2truefalsefalse41700000004170000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying amount at the balance sheet date of long-lived asset under construction that include construction costs to date on capital projects that have not been completed and assets being constructed that are not ready to be placed into service.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 truefalseConstruction work in progress26false0us-gaap_PropertyPlantAndEquipmentNetus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse4200200000042002000000falsefalsefalsefalsefalse2truefalsefalse3923000000039230000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, and production equipment.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 13 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 12 -Paragraph 5 -Subparagraph b, c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 8 -Article 7 truefalseTotal property, plant, and equipment27true0us-gaap_LongTermInvestmentsAbstractus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseOther Property and Investments:28false0us-gaap_DecommissioningFundInvestmentsus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse13700000001370000000falsefalsefalsefalsefalse2truefalsefalse10700000001070000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryDecommission fund to pay for the costs of decontaminating and decommissioning of facilities through collection of revenues derived from utility assessments and government appropriations. Decommission fund investment for the process whereby a power station, at the end of its economic life, is taken permanently out of service and its site made available for other purposes. In the case of a nuclear station this comprises three different states of clearance. Immediately after the final closure, radioactive material such as nuclear fuel and operational waste is removed and the buildings surrounding the reactor shield are dismantled and finally the reactor itself is dismantled.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 12 -Article 5 falsefalseNuclear decommissioning trusts, at fair value29false0us-gaap_LeveragedLeasesBalanceSheetInvestmentInLeveragedLeasesNetus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse624000000624000000falsefalsefalsefalsefalse2truefalsefalse610000000610000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryRentals receivable and estimated residual value of leased assets less principal and interest on nonrecourse debt, unearned income, and deferred taxes.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 47 falsefalseLeveraged leases30false0us-gaap_OtherLongTermInvestmentsus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse277000000277000000falsefalsefalsefalsefalse2truefalsefalse283000000283000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryOther noncurrent investments not otherwise specified in the taxonomy, not including investments in marketable securities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 12 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Subparagraph f -Article 7 truefalseMiscellaneous property and investments31false0us-gaap_LongTermInvestmentsus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse22710000002271000000falsefalsefalsefalsefalse2truefalsefalse19630000001963000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle).No authoritative reference available.truefalseTotal other property and investments32true0so_DeferredChargesAndOtherAssetsAbstractsofalsenadurationDeferred Charges and Other Assets.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringDeferred Charges and Other Assets.falsefalseDeferred Charges and Other Assets:33false0so_DeferredChargesRelatedToIncomeTaxessofalsedebitinstantNoncurrent regulatory assets associated with deferred income tax liabilities that are expected to be recovered from customers...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse12800000001280000000falsefalsefalsefalsefalse2truefalsefalse10470000001047000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryNoncurrent regulatory assets associated with deferred income tax liabilities that are expected to be recovered from customers through the ratemaking process.No authoritative reference available.falsefalseDeferred charges related to income taxes34false0us-gaap_PrepaidPensionCostsus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse8800000088000000falsefalsefalsefalsefalse2truefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCumulative employer's contributions in excess of net pension cost recognized, before the adoption of the recognition provisions of FAS 158. Under FAS 158, prepaid pension costs are no longer recognized in the statement of financial position. Note that there is a separate concept for noncurrent assets relating to defined benefit pension and other defined benefit postretirement plans for use under the recognition provisions of FAS 158.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph c(4) falsefalsePrepaid pension costs35false0us-gaap_UnamortizedDebtIssuanceExpenseus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse178000000178000000falsefalsefalsefalsefalse2truefalsefalse208000000208000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.No authoritative reference available.falsefalseUnamortized debt issuance expense36false0us-gaap_UnamortizedLossReacquiredDebtNoncurrentus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse274000000274000000falsefalsefalsefalsefalse2truefalsefalse255000000255000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryUnamortized Loss on Reacquired Debt is the loss incurred upon reacquisition or refinancing of debt, is treated as a deferred charge and amortized over the life of the new debt issued.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 71 -Paragraph 9 falsefalseUnamortized loss on reacquired debt37false0so_DeferredUnderRecoveredRegulatoryClauseRevenuessofalsedebitinstantCarrying amount at the balance sheet date of underrecovered fuel costs allowed to be deferred by regulatory authorities, that...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse218000000218000000falsefalsefalsefalsefalse2truefalsefalse373000000373000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying amount at the balance sheet date of underrecovered fuel costs allowed to be deferred by regulatory authorities, that are expected to be recoverable through rate adjustments after one year.No authoritative reference available.falsefalseDeferred under recovered regulatory clause revenues38false0so_OtherRegulatoryAssetsDeferredsofalsedebitinstantCarrying amount of other regulatory assets (not elsewhere identified) as of the balance sheet date of capitalized costs of...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse24020000002402000000falsefalsefalsefalsefalse2truefalsefalse27020000002702000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying amount of other regulatory assets (not elsewhere identified) 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.No authoritative reference available.falsefalseOther regulatory assets, deferred39false0us-gaap_OtherAssetsNoncurrentus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse436000000436000000falsefalsefalsefalsefalse2truefalsefalse395000000395000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the balance sheet due to materiality considerations. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 truefalseOther deferred charges and assets40false0so_TotalDeferredChargesAndOtherAssetssofalsedebitinstantSum of the carrying amounts as of the balance sheet date of all assets, excluding Property, Plant, and Equipment and Other...falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse48760000004876000000falsefalsefalsefalsefalse2truefalsefalse49800000004980000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetarySum of the carrying amounts as of the balance sheet date of all assets, excluding Property, Plant, and Equipment and Other Property and Investments, that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer.No authoritative reference available.truefalseTotal deferred charges and other assets41false0us-gaap_Assetsus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse5503200000055032000000falsefalsefalsefalsefalse2truefalsefalse5204600000052046000000falsefalsefalsefalsefalseMonetaryxbrli: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 Statement of Financial Accounting Concepts (CON) -Number 6 -Paragraph 25 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 12 -Article 7 truefalseTotal Assets43true0us-gaap_LiabilitiesCurrentAbstractus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseCurrent Liabilities:44false0us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse13010000001301000000falsefalsefalsefalsefalse2truefalsefalse11130000001113000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryObligation related to long-term debt (excluding convertible debt) and capital leases, the portion which is due in one year or less in the future.No authoritative reference available.falsefalseSecurities due within one year45false0us-gaap_ShortTermBorrowingsus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse12970000001297000000falsefalsefalsefalsefalse2truefalsefalse639000000639000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryReflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 13 -Subparagraph 2, 3 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Subparagraph a(1) -Article 7 falsefalseNotes payable46false0us-gaap_AccountsPayableCurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse12750000001275000000falsefalsefalsefalsefalse2truefalsefalse13290000001329000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 falsefalseAccounts payable47false0us-gaap_CustomerDepositsCurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse332000000332000000falsefalsefalsefalsefalse2truefalsefalse331000000331000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe current portion, due within one year or the normal operating cycle, if longer, of money or property received from customers which is either to be returned upon satisfactory contract completion or applied to customer receivables in accordance with the terms of the contract or the understandings.No authoritative reference available.falsefalseCustomer deposits48true0us-gaap_TaxesPayableCurrentAbstractus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseAccrued taxes --49false0us-gaap_AccruedIncomeTaxesCurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse80000008000000falsefalsefalsefalsefalse2truefalsefalse1300000013000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying amount as of the balance sheet date of the unpaid sum of the known and estimated amounts payable to satisfy all currently due domestic and foreign income tax obligations.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Subparagraph b(1) -Article 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Interpretation (FIN) -Number 48 -Paragraph 15, 21 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Section Appendix E -Paragraph 289 falsefalseAccrued income taxes50false0so_UnrecognizedTaxBenefitsAccruedTaxessofalsecreditinstantLiability associated with tax benefits that do not currently fully meet the "more likely than not" threshold as defined by...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse187000000187000000falsefalsefalsefalsefalse2truefalsefalse166000000166000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryLiability associated with tax benefits that do not currently fully meet the "more likely than not" threshold as defined by FIN 48. This line item includes both federal and state taxes.No authoritative reference available.falsefalseUnrecognized tax benefits51false0us-gaap_AccrualForTaxesOtherThanIncomeTaxesCurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse440000000440000000falsefalsefalsefalsefalse2truefalsefalse398000000398000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying value as of the balance sheet date of obligations incurred and payable for real and property taxes. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 10 -Section A -Paragraph 16 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 falsefalseOther accrued taxes52false0us-gaap_InterestPayableCurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse225000000225000000falsefalsefalsefalsefalse2truefalsefalse218000000218000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying value as of the balance sheet date of [accrued] interest payable on all forms of debt, including trade payables, that has been incurred and is unpaid. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 falsefalseAccrued interest53false0us-gaap_AccruedVacationCurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse194000000194000000falsefalsefalsefalsefalse2truefalsefalse184000000184000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying value as of the balance sheet date of obligations incurred and payable for unused vacation time owed to employees based on the entity's vacation benefit given to its employees. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 43 -Paragraph 13 falsefalseAccrued vacation pay54false0us-gaap_AccruedSalariesCurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse438000000438000000falsefalsefalsefalsefalse2truefalsefalse248000000248000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying value as of the balance sheet date of the obligations incurred through that date and payable for employees' services provided. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 7, 8 falsefalseAccrued compensation55false0us-gaap_DerivativeInstrumentsAndHedgesLiabilitiesus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse152000000152000000falsefalsefalsefalsefalse2truefalsefalse125000000125000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetarySum as of the balance sheet date of the (a) fair values of all liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments, and (b) the carrying amounts of the liabilities arising from financial instruments or contracts used to mitigate a specified risk (hedge), and which are expected to be extinguished or otherwise disposed of within a year or the normal operating cycle, if longer, net of the effects of master netting arrangements.No authoritative reference available.falsefalseLiabilities from risk management activities56false0so_OtherRegulatoryLiabilitiesCurrentsofalsecreditinstantThe amount for other current regulatory liabilities not elsewhere included. Regulatory liabilities represent probable future...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse8800000088000000falsefalsefalsefalsefalse2truefalsefalse528000000528000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount for other current regulatory liabilities not elsewhere included. Regulatory liabilities represent probable future reductions in revenues associated with amounts that are expected to be credited to customers through the ratemaking process. These revenues are expected to be credited within one year.No authoritative reference available.falsefalseOther regulatory liabilities, current57false0us-gaap_OtherLiabilitiesCurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse535000000535000000falsefalsefalsefalsefalse2truefalsefalse292000000292000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAggregate carrying amount, as of the balance sheet date, of current obligations not separately disclosed in the balance sheet due to materiality considerations. Current liabilities are expected to be paid within one year (or the normal operating cycle, if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 6 -Paragraph 15 truefalseOther current liabilities58false0us-gaap_LiabilitiesCurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse64720000006472000000falsefalsefalsefalsefalse2truefalsefalse55840000005584000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTotal obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 21 -Article 5 truefalseTotal current liabilities59false0us-gaap_LongTermDebtAndCapitalLeaseObligationsus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse1815400000018154000000falsefalsefalsefalsefalse2truefalsefalse1813100000018131000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetarySum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year or the normal operating cycle, if longer plus capital lease obligations due to be paid more than one year after the balance sheet date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 6 -Section H truefalseLong-Term Debt (See accompanying statements)60true0so_DeferredCreditsAndOtherLiabilitiesAbstractsofalsenadurationDeferred Credits and Other Liabilities.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringDeferred Credits and Other Liabilities.falsefalseDeferred Credits and Other Liabilities:61false0us-gaap_DeferredTaxLiabilitiesNoncurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse75540000007554000000falsefalsefalsefalsefalse2truefalsefalse64550000006455000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryRepresents the noncurrent portion of deferred tax liabilities, which result from applying the applicable tax rate to net taxable temporary differences pertaining to each jurisdiction to which the entity is obligated to pay income tax. A noncurrent taxable temporary difference is a difference between the tax basis and the carrying amount of a noncurrent asset or liability in the financial statements prepared in accordance with generally accepted accounting principles. In a classified statement of financial position, an enterprise shall separate deferred tax liabilities and assets into a current amount and a noncurrent amount. Deferred tax liabilities and assets shall be classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, shall be classified according to the expected reversal date of the temporary difference.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 41, 42 falsefalseAccumulated deferred income taxes62false0so_DeferredCreditsRelatedToIncomeTaxessofalsecreditinstantNoncurrent regulatory liabilities associated with deferred income tax liabilities. Regulatory liabilities represent probable...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse235000000235000000falsefalsefalsefalsefalse2truefalsefalse248000000248000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryNoncurrent regulatory liabilities associated with deferred income tax liabilities. Regulatory liabilities represent probable future reductions in revenues associated with amounts that are expected to be credited to customers through the ratemaking process. These revenues are not expected to be credited within one year or the normal operating cycle if longer.No authoritative reference available.falsefalseDeferred credits related to income taxes63false0us-gaap_AccumulatedDeferredInvestmentTaxCreditus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse509000000509000000falsefalsefalsefalsefalse2truefalsefalse448000000448000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe noncurrent portion of the reserve for accumulated deferred investment tax credits as of the balance sheet date. This is the remaining investment credit, which will reduce the cost of services collected from ratepayers by a ratable portion over the investment's regulatory life.No authoritative reference available.falsefalseAccumulated deferred investment tax credits64false0us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse15800000001580000000falsefalsefalsefalsefalse2truefalsefalse23040000002304000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis represents the noncurrent liability for underfunded plans recognized in the balance sheet that is associated with the defined benefit pension plans and other postretirement defined benefit plans.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph c Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 6 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 3 falsefalseEmployee benefit obligations65false0us-gaap_AssetRetirementObligationsNoncurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse12570000001257000000falsefalsefalsefalsefalse2truefalsefalse12010000001201000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryNoncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 143 -Paragraph 3, 10, 22 falsefalseAsset retirement obligations66false0so_OtherCostOfRemovalObligationssofalsecreditinstantThe regulatory liability as of the balance sheet date for the amount recovered from ratepayers for removal costs associated...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse11580000001158000000falsefalsefalsefalsefalse2truefalsefalse10910000001091000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe regulatory liability as of the balance sheet date for the amount recovered from ratepayers for removal costs associated with utility plant in service which are not recognized as a liability.No authoritative reference available.falsefalseOther cost of removal obligations67false0so_OtherRegulatoryLiabilitiesDeferredsofalsecreditinstantThe amount for other noncurrent regulatory liabilities not elsewhere included. Regulatory liabilities represent probable...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse312000000312000000falsefalsefalsefalsefalse2truefalsefalse278000000278000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount for other noncurrent regulatory liabilities not elsewhere included. Regulatory liabilities represent probable future reductions in revenues associated with amounts that are expected to be credited to customers through the ratemaking process. These revenues are not expected to be credited within one year or the normal operating cycle if longer.No authoritative reference available.falsefalseOther regulatory liabilities, deferred68false0us-gaap_OtherLiabilitiesNoncurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse517000000517000000falsefalsefalsefalsefalse2truefalsefalse346000000346000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAggregate carrying amount, as of the balance sheet date, of noncurrent obligations not separately disclosed in the balance sheet due to materiality considerations. Noncurrent liabilities are expected to be paid after one year (or the normal operating cycle, if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 24 -Article 5 truefalseOther deferred credits and liabilities69false0so_TotalDeferredCreditsAndOtherLiabilitiessofalsecreditinstantTotal obligations, excluding Long-term Debt, incurred as part of normal operations that is expected to be repaid beyond the...falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse1312200000013122000000falsefalsefalsefalsefalse2truefalsefalse1237100000012371000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTotal obligations, excluding Long-term Debt, incurred as part of normal operations that is expected to be repaid beyond the following twelve months or one business cycle.No authoritative reference available.truefalseTotal deferred credits and other liabilities70false0us-gaap_Liabilitiesus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse3774800000037748000000falsefalsefalsefalsefalse2truefalsefalse3608600000036086000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetarySum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.No authoritative reference available.truefalseTotal Liabilities71false0us-gaap_TemporaryEquityCarryingAmountus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse375000000375000000falsefalsefalsefalsefalse2truefalsefalse375000000375000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe carrying value (book value) of an entity's issued and outstanding stock which is not included within permanent equity in Stockholders Equity. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with a put option held by an ESOP and stock redeemable by a holder only in the event of a change in control of the issuer.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph i -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number D-98 -Paragraph 2 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 28 -Subparagraph a -Article 5 truefalseRedeemable Preferred Stock of Subsidiaries (See accompanying statements)72false0us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse1690900000016909000000falsefalsefalsefalsefalse2truefalsefalse1558500000015585000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTotal of Stockholders' Equity (deficit) items, net of receivables from officers, directors owners, and affiliates of the entity including portions attributable to both the parent and noncontrolling interests (previously referred to as minority interest), if any. 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