XML 91 R9.htm IDEA: XBRL DOCUMENT v2.4.1.9
Consolidated Statements of Cash Flows (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Operating Activites      
Net Income (Loss) $ 1,638,000,000us-gaap_ProfitLoss $ 1,484,000,000us-gaap_ProfitLoss $ 1,262,000,000us-gaap_ProfitLoss
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:      
Depreciation and Amortization 1,929,000,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization 1,743,000,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization 1,782,000,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
Deferred Income Taxes 878,000,000us-gaap_DeferredIncomeTaxExpenseBenefit 709,000,000us-gaap_DeferredIncomeTaxExpenseBenefit 636,000,000us-gaap_DeferredIncomeTaxExpenseBenefit
Asset Impairments and Other Related Charges 0us-gaap_OtherAssetImpairmentCharges 226,000,000us-gaap_OtherAssetImpairmentCharges 300,000,000us-gaap_OtherAssetImpairmentCharges
Carrying Costs Income (33,000,000)aep_CarryingCostsIncome (30,000,000)aep_CarryingCostsIncome (53,000,000)aep_CarryingCostsIncome
Allowance for Equity Funds Used During Construction (103,000,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity (73,000,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity (93,000,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
Mark-to-Market of Risk Management Contracts (53,000,000)us-gaap_UnrealizedGainLossOnDerivatives 38,000,000us-gaap_UnrealizedGainLossOnDerivatives 57,000,000us-gaap_UnrealizedGainLossOnDerivatives
Amortization of Nuclear Fuel 144,000,000aep_AmortizationOfNuclearFuel 131,000,000aep_AmortizationOfNuclearFuel 136,000,000aep_AmortizationOfNuclearFuel
Pension and Postemployment Benefit Reserves 80,000,000us-gaap_PensionAndOtherPostretirementBenefitExpense 172,000,000us-gaap_PensionAndOtherPostretirementBenefitExpense 120,000,000us-gaap_PensionAndOtherPostretirementBenefitExpense
Pension Contributions to Qualified Plan Trust (71,000,000)us-gaap_PensionContributions 0us-gaap_PensionContributions (200,000,000)us-gaap_PensionContributions
Property Taxes (42,000,000)us-gaap_AmortizationOfDeferredPropertyTaxes (35,000,000)us-gaap_AmortizationOfDeferredPropertyTaxes (19,000,000)us-gaap_AmortizationOfDeferredPropertyTaxes
Fuel Over/Under-Recovery, Net (36,000,000)aep_FuelOverUnderRecoveryNet 62,000,000aep_FuelOverUnderRecoveryNet 157,000,000aep_FuelOverUnderRecoveryNet
Deferral of Ohio Capacity Costs, Net (114,000,000)aep_DeferralOfOhioCapacityCosts (214,000,000)aep_DeferralOfOhioCapacityCosts (65,000,000)aep_DeferralOfOhioCapacityCosts
Change in Other Noncurrent Assets 26,000,000us-gaap_IncreaseDecreaseInOtherNoncurrentAssets (184,000,000)us-gaap_IncreaseDecreaseInOtherNoncurrentAssets (171,000,000)us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
Change in Other Noncurrent Liabilities 242,000,000us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities (169,000,000)us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities 7,000,000us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities
Changes in Certain Components of Working Capital:      
Accounts Receivable, Net (72,000,000)us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables 5,000,000us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables (16,000,000)us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables
Fuel, Materials and Supplies 102,000,000us-gaap_IncreaseDecreaseInInventories 122,000,000us-gaap_IncreaseDecreaseInInventories (224,000,000)us-gaap_IncreaseDecreaseInInventories
Accounts Payable (80,000,000)us-gaap_IncreaseDecreaseInAccountsPayable 95,000,000us-gaap_IncreaseDecreaseInAccountsPayable (60,000,000)us-gaap_IncreaseDecreaseInAccountsPayable
Accrued Taxes, Net 4,000,000us-gaap_IncreaseDecreaseInAccruedTaxesPayable 85,000,000us-gaap_IncreaseDecreaseInAccruedTaxesPayable 174,000,000us-gaap_IncreaseDecreaseInAccruedTaxesPayable
Other Current Assets (36,000,000)us-gaap_IncreaseDecreaseInOtherCurrentAssets 5,000,000us-gaap_IncreaseDecreaseInOtherCurrentAssets (3,000,000)us-gaap_IncreaseDecreaseInOtherCurrentAssets
Other Current Liabilities 210,000,000us-gaap_IncreaseDecreaseInOtherCurrentLiabilities (66,000,000)us-gaap_IncreaseDecreaseInOtherCurrentLiabilities 77,000,000us-gaap_IncreaseDecreaseInOtherCurrentLiabilities
Net Cash Flows from (Used for) Operating Activities 4,613,000,000us-gaap_NetCashProvidedByUsedInOperatingActivities 4,106,000,000us-gaap_NetCashProvidedByUsedInOperatingActivities 3,804,000,000us-gaap_NetCashProvidedByUsedInOperatingActivities
Investing Activities      
Construction Expenditures (4,134,000,000)us-gaap_PaymentsForConstructionInProcess (3,624,000,000)us-gaap_PaymentsForConstructionInProcess (3,025,000,000)us-gaap_PaymentsForConstructionInProcess
Change in Other Temporary Investments, Net (31,000,000)aep_ChangeInOtherTemporaryInvestmentsNet (11,000,000)aep_ChangeInOtherTemporaryInvestmentsNet (27,000,000)aep_ChangeInOtherTemporaryInvestmentsNet
Purchases of Investment Securities (1,088,000,000)us-gaap_PaymentsToAcquireInvestments (927,000,000)us-gaap_PaymentsToAcquireInvestments (1,047,000,000)us-gaap_PaymentsToAcquireInvestments
Sales of Investment Securities 1,032,000,000us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments 858,000,000us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments 988,000,000us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments
Acquisitions of Nuclear Fuel (116,000,000)us-gaap_PaymentsForNuclearFuel (154,000,000)us-gaap_PaymentsForNuclearFuel (107,000,000)us-gaap_PaymentsForNuclearFuel
Acquisitions of Assets (65,000,000)us-gaap_PaymentsToAcquirePropertyPlantAndEquipment (32,000,000)us-gaap_PaymentsToAcquirePropertyPlantAndEquipment (94,000,000)us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
Insurance Proceeds Related to Cook Plant Fire 0us-gaap_ProceedsFromInsuranceSettlementInvestingActivities 72,000,000us-gaap_ProceedsFromInsuranceSettlementInvestingActivities 0us-gaap_ProceedsFromInsuranceSettlementInvestingActivities
Proceeds from Sales of Assets 6,000,000us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment 21,000,000us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment 18,000,000us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment
Other Investing Activities (10,000,000)us-gaap_PaymentsForProceedsFromOtherInvestingActivities (21,000,000)us-gaap_PaymentsForProceedsFromOtherInvestingActivities (97,000,000)us-gaap_PaymentsForProceedsFromOtherInvestingActivities
Net Cash Flows from (Used for) Investing Activities (4,406,000,000)us-gaap_NetCashProvidedByUsedInInvestingActivities (3,818,000,000)us-gaap_NetCashProvidedByUsedInInvestingActivities (3,391,000,000)us-gaap_NetCashProvidedByUsedInInvestingActivities
Financing Activities      
Issuance of Common Stock, Net 73,000,000us-gaap_ProceedsFromIssuanceOfCommonStock 84,000,000us-gaap_ProceedsFromIssuanceOfCommonStock 83,000,000us-gaap_ProceedsFromIssuanceOfCommonStock
Issuance of Long-term Debt 2,067,000,000us-gaap_ProceedsFromIssuanceOfLongTermDebt 3,207,000,000us-gaap_ProceedsFromIssuanceOfLongTermDebt 2,856,000,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
Credit Facility Borrowings 0us-gaap_ProceedsFromShortTermDebtMaturingInMoreThanThreeMonths 17,000,000us-gaap_ProceedsFromShortTermDebtMaturingInMoreThanThreeMonths 25,000,000us-gaap_ProceedsFromShortTermDebtMaturingInMoreThanThreeMonths
Change in Short-term Debt, Net 589,000,000us-gaap_ProceedsFromRepaymentsOfShortTermDebtMaturingInThreeMonthsOrLess (221,000,000)us-gaap_ProceedsFromRepaymentsOfShortTermDebtMaturingInThreeMonthsOrLess (654,000,000)us-gaap_ProceedsFromRepaymentsOfShortTermDebtMaturingInThreeMonthsOrLess
Retirement of Long-term Debt (1,780,000,000)us-gaap_RepaymentsOfLongTermDebt (2,598,000,000)us-gaap_RepaymentsOfLongTermDebt (1,643,000,000)us-gaap_RepaymentsOfLongTermDebt
Credit Facility Repayments 0us-gaap_RepaymentsOfShortTermDebtMaturingInMoreThanThreeMonths (20,000,000)us-gaap_RepaymentsOfShortTermDebtMaturingInMoreThanThreeMonths (40,000,000)us-gaap_RepaymentsOfShortTermDebtMaturingInMoreThanThreeMonths
Proceeds from Nuclear Fuel Sale/Leaseback 0us-gaap_SaleLeasebackTransactionGrossProceedsFinancingActivities 110,000,000us-gaap_SaleLeasebackTransactionGrossProceedsFinancingActivities 0us-gaap_SaleLeasebackTransactionGrossProceedsFinancingActivities
Principal Payments for Capital Lease Obligations (120,000,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations (82,000,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations (71,000,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
Dividends Paid on Common Stock (998,000,000)us-gaap_PaymentsOfDividendsCommonStock (954,000,000)us-gaap_PaymentsOfDividendsCommonStock (916,000,000)us-gaap_PaymentsOfDividendsCommonStock
Other Financing Activities 7,000,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities 8,000,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities 5,000,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
Net Cash Flows from (Used for) Financing Activities (162,000,000)us-gaap_NetCashProvidedByUsedInFinancingActivities (449,000,000)us-gaap_NetCashProvidedByUsedInFinancingActivities (355,000,000)us-gaap_NetCashProvidedByUsedInFinancingActivities
Net Increase (Decrease) in Cash and Cash Equivalents 45,000,000us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease (161,000,000)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease 58,000,000us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
Cash and Cash Equivalents at Beginning of Period 118,000,000us-gaap_CashAndCashEquivalentsAtCarryingValue 279,000,000us-gaap_CashAndCashEquivalentsAtCarryingValue 221,000,000us-gaap_CashAndCashEquivalentsAtCarryingValue
Cash and Cash Equivalents at End of Period 163,000,000us-gaap_CashAndCashEquivalentsAtCarryingValue 118,000,000us-gaap_CashAndCashEquivalentsAtCarryingValue 279,000,000us-gaap_CashAndCashEquivalentsAtCarryingValue
Supplementary Information      
Cash Paid for Interest, Net of Capitalized Amounts 838,000,000us-gaap_InterestPaidNet 882,000,000us-gaap_InterestPaidNet 931,000,000us-gaap_InterestPaidNet
Net Cash Paid (Received) for Income Taxes 117,000,000us-gaap_IncomeTaxesPaidNet (55,000,000)us-gaap_IncomeTaxesPaidNet (82,000,000)us-gaap_IncomeTaxesPaidNet
Noncash Acquisitions Under Capital Leases 135,000,000us-gaap_CapitalLeaseObligationsIncurred 182,000,000us-gaap_CapitalLeaseObligationsIncurred 63,000,000us-gaap_CapitalLeaseObligationsIncurred
Construction Expenditures Included in Current Liabilities as of December 31, 559,000,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid 492,000,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid 439,000,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid
Noncash Assumption of Liabilities Related to Acquisitions 0us-gaap_LiabilitiesAssumed1 0us-gaap_LiabilitiesAssumed1 56,000,000us-gaap_LiabilitiesAssumed1
Acquisition of Nuclear Fuel Included in Current Liabilities as of December 31, 45,000,000aep_AcquisitionOfNuclearFuelIncludedInCurrentLiabilities 0aep_AcquisitionOfNuclearFuelIncludedInCurrentLiabilities 35,000,000aep_AcquisitionOfNuclearFuelIncludedInCurrentLiabilities
Expected Reimbursement For Spent Nuclear Fuel Dry Cask Storage 3,000,000aep_ExpectedReimbursementForSpentNuclearFuelDryCaskStorage 4,000,000aep_ExpectedReimbursementForSpentNuclearFuelDryCaskStorage 30,000,000aep_ExpectedReimbursementForSpentNuclearFuelDryCaskStorage
Appalachian Power Co [Member]      
Operating Activites      
Net Income (Loss) 215,415,000us-gaap_ProfitLoss
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
193,211,000us-gaap_ProfitLoss
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
257,503,000us-gaap_ProfitLoss
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:      
Depreciation and Amortization 400,882,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
342,643,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
344,293,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Deferred Income Taxes 144,651,000us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
75,714,000us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
138,460,000us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Asset Impairments and Other Related Charges 0us-gaap_OtherAssetImpairmentCharges
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
39,283,000us-gaap_OtherAssetImpairmentCharges
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
0us-gaap_OtherAssetImpairmentCharges
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Carrying Costs Income (3,045,000)aep_CarryingCostsIncome
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(8,086,000)aep_CarryingCostsIncome
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(24,602,000)aep_CarryingCostsIncome
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Amortization (Deferral) of Storm Costs 6,816,000aep_DeferralOfStormCosts
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
36,068,000aep_DeferralOfStormCosts
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(87,992,000)aep_DeferralOfStormCosts
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Allowance for Equity Funds Used During Construction (7,053,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(2,353,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(1,684,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Mark-to-Market of Risk Management Contracts 3,302,000us-gaap_UnrealizedGainLossOnDerivatives
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
12,288,000us-gaap_UnrealizedGainLossOnDerivatives
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
10,130,000us-gaap_UnrealizedGainLossOnDerivatives
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Pension Contributions to Qualified Plan Trust (8,963,000)us-gaap_PensionContributions
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
0us-gaap_PensionContributions
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(25,199,000)us-gaap_PensionContributions
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Fuel Over/Under-Recovery, Net (119,592,000)aep_FuelOverUnderRecoveryNet
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
59,174,000aep_FuelOverUnderRecoveryNet
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
96,774,000aep_FuelOverUnderRecoveryNet
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Change in Regulatory Assets (6,167,000)aep_ChangeInRegulatoryAssets
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(10,108,000)aep_ChangeInRegulatoryAssets
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(31,104,000)aep_ChangeInRegulatoryAssets
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Change in Other Noncurrent Assets (12,532,000)us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(22,894,000)us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(21,724,000)us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Change in Other Noncurrent Liabilities 48,748,000us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
15,707,000us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
24,206,000us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Changes in Certain Components of Working Capital:      
Accounts Receivable, Net 68,586,000us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
12,470,000us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
42,161,000us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Fuel, Materials and Supplies 75,983,000us-gaap_IncreaseDecreaseInInventories
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
28,042,000us-gaap_IncreaseDecreaseInInventories
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(40,268,000)us-gaap_IncreaseDecreaseInInventories
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Accounts Payable (62,764,000)us-gaap_IncreaseDecreaseInAccountsPayable
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(31,951,000)us-gaap_IncreaseDecreaseInAccountsPayable
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
12,547,000us-gaap_IncreaseDecreaseInAccountsPayable
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Accrued Taxes, Net (5,380,000)us-gaap_IncreaseDecreaseInAccruedTaxesPayable
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
81,228,000us-gaap_IncreaseDecreaseInAccruedTaxesPayable
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(14,396,000)us-gaap_IncreaseDecreaseInAccruedTaxesPayable
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Other Current Assets (962,000)us-gaap_IncreaseDecreaseInOtherCurrentAssets
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
5,626,000us-gaap_IncreaseDecreaseInOtherCurrentAssets
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
3,706,000us-gaap_IncreaseDecreaseInOtherCurrentAssets
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Other Current Liabilities 23,812,000us-gaap_IncreaseDecreaseInOtherCurrentLiabilities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(11,667,000)us-gaap_IncreaseDecreaseInOtherCurrentLiabilities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
7,234,000us-gaap_IncreaseDecreaseInOtherCurrentLiabilities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Net Cash Flows from (Used for) Operating Activities 761,737,000us-gaap_NetCashProvidedByUsedInOperatingActivities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
814,395,000us-gaap_NetCashProvidedByUsedInOperatingActivities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
690,045,000us-gaap_NetCashProvidedByUsedInOperatingActivities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Investing Activities      
Construction Expenditures (497,400,000)us-gaap_PaymentsForConstructionInProcess
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(380,974,000)us-gaap_PaymentsForConstructionInProcess
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(469,052,000)us-gaap_PaymentsForConstructionInProcess
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Change in Advances to Affiliates, Net 43,966,000us-gaap_IncreaseDecreaseInNotesReceivableRelatedParties
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(69,461,000)us-gaap_IncreaseDecreaseInNotesReceivableRelatedParties
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(1,016,000)us-gaap_IncreaseDecreaseInNotesReceivableRelatedParties
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Other Investing Activities (5,460,000)us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(1,231,000)us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
7,209,000us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Net Cash Flows from (Used for) Investing Activities (458,894,000)us-gaap_NetCashProvidedByUsedInInvestingActivities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(451,666,000)us-gaap_NetCashProvidedByUsedInInvestingActivities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(462,859,000)us-gaap_NetCashProvidedByUsedInInvestingActivities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Financing Activities      
Issuance of Long-term Debt 394,189,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
444,437,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
339,374,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Change in Advances from Affiliates, Net 0us-gaap_IncreaseDecreaseInNotesPayableRelatedParties
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(173,965,000)us-gaap_IncreaseDecreaseInNotesPayableRelatedParties
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(24,283,000)us-gaap_IncreaseDecreaseInNotesPayableRelatedParties
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Retirement of Long-term Debt (612,710,000)us-gaap_RepaymentsOfLongTermDebt
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(345,029,000)us-gaap_RepaymentsOfLongTermDebt
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(364,875,000)us-gaap_RepaymentsOfLongTermDebt
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Principal Payments for Capital Lease Obligations (5,618,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(5,550,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(6,496,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Dividends Paid on Common Stock (80,000,000)us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(285,000,000)us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(170,000,000)us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Other Financing Activities 1,164,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
1,547,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
353,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Net Cash Flows from (Used for) Financing Activities (302,975,000)us-gaap_NetCashProvidedByUsedInFinancingActivities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(363,560,000)us-gaap_NetCashProvidedByUsedInFinancingActivities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(225,927,000)us-gaap_NetCashProvidedByUsedInFinancingActivities
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Net Increase (Decrease) in Cash and Cash Equivalents (132,000)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(831,000)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
1,259,000us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Cash and Cash Equivalents at Beginning of Period 2,745,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
3,576,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
2,317,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Cash and Cash Equivalents at End of Period 2,613,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
2,745,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
3,576,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Supplementary Information      
Cash Paid for Interest, Net of Capitalized Amounts 196,716,000us-gaap_InterestPaidNet
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
184,584,000us-gaap_InterestPaidNet
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
200,383,000us-gaap_InterestPaidNet
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Net Cash Paid (Received) for Income Taxes 15,899,000us-gaap_IncomeTaxesPaidNet
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
(27,759,000)us-gaap_IncomeTaxesPaidNet
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
31,418,000us-gaap_IncomeTaxesPaidNet
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Noncash Acquisitions Under Capital Leases 4,908,000us-gaap_CapitalLeaseObligationsIncurred
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
4,351,000us-gaap_CapitalLeaseObligationsIncurred
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
3,366,000us-gaap_CapitalLeaseObligationsIncurred
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Construction Expenditures Included in Current Liabilities as of December 31, 72,009,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
50,829,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
62,177,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Noncash Contribution of Amos Plant from Parent 0aep_NoncashContributionsFromParent
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
235,810,000aep_NoncashContributionsFromParent
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
0aep_NoncashContributionsFromParent
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Indiana Michigan Power Co [Member]      
Operating Activites      
Net Income (Loss) 155,647,000us-gaap_ProfitLoss
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
177,504,000us-gaap_ProfitLoss
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
118,457,000us-gaap_ProfitLoss
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:      
Depreciation and Amortization 200,196,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
177,727,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
146,619,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Deferred Income Taxes 70,225,000us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
129,109,000us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
53,067,000us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Amortization (Deferral) of Incremental Nuclear Refueling Outage Expenses, Net 19,967,000aep_DeferralOfIncrementalNuclearRefuelingOutageExpensesNet
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(31,328,000)aep_DeferralOfIncrementalNuclearRefuelingOutageExpensesNet
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
13,899,000aep_DeferralOfIncrementalNuclearRefuelingOutageExpensesNet
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Allowance for Equity Funds Used During Construction (18,873,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(19,943,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(9,724,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Mark-to-Market of Risk Management Contracts (6,141,000)us-gaap_UnrealizedGainLossOnDerivatives
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
12,496,000us-gaap_UnrealizedGainLossOnDerivatives
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
12,164,000us-gaap_UnrealizedGainLossOnDerivatives
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Amortization of Nuclear Fuel 144,236,000aep_AmortizationOfNuclearFuel
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
130,629,000aep_AmortizationOfNuclearFuel
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
135,905,000aep_AmortizationOfNuclearFuel
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Fuel Over/Under-Recovery, Net 7,791,000aep_FuelOverUnderRecoveryNet
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
3,254,000aep_FuelOverUnderRecoveryNet
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
4,175,000aep_FuelOverUnderRecoveryNet
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Change in Other Noncurrent Assets (72,900,000)us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(57,106,000)us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(2,347,000)us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Change in Other Noncurrent Liabilities 83,147,000us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
37,310,000us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
36,524,000us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Changes in Certain Components of Working Capital:      
Accounts Receivable, Net 32,272,000us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
1,445,000us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
34,431,000us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Fuel, Materials and Supplies 7,813,000us-gaap_IncreaseDecreaseInInventories
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(8,848,000)us-gaap_IncreaseDecreaseInInventories
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(19,321,000)us-gaap_IncreaseDecreaseInInventories
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Accounts Payable (20,426,000)us-gaap_IncreaseDecreaseInAccountsPayable
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(11,151,000)us-gaap_IncreaseDecreaseInAccountsPayable
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
15,959,000us-gaap_IncreaseDecreaseInAccountsPayable
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Accrued Taxes, Net 24,812,000us-gaap_IncreaseDecreaseInAccruedTaxesPayable
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(23,887,000)us-gaap_IncreaseDecreaseInAccruedTaxesPayable
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
16,897,000us-gaap_IncreaseDecreaseInAccruedTaxesPayable
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Other Current Assets 10,575,000us-gaap_IncreaseDecreaseInOtherCurrentAssets
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
21,287,000us-gaap_IncreaseDecreaseInOtherCurrentAssets
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(10,504,000)us-gaap_IncreaseDecreaseInOtherCurrentAssets
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Other Current Liabilities 6,929,000us-gaap_IncreaseDecreaseInOtherCurrentLiabilities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
575,000us-gaap_IncreaseDecreaseInOtherCurrentLiabilities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
11,717,000us-gaap_IncreaseDecreaseInOtherCurrentLiabilities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Net Cash Flows from (Used for) Operating Activities 645,270,000us-gaap_NetCashProvidedByUsedInOperatingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
539,073,000us-gaap_NetCashProvidedByUsedInOperatingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
557,918,000us-gaap_NetCashProvidedByUsedInOperatingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Investing Activities      
Construction Expenditures (484,721,000)us-gaap_PaymentsForConstructionInProcess
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(508,857,000)us-gaap_PaymentsForConstructionInProcess
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(317,284,000)us-gaap_PaymentsForConstructionInProcess
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Change in Advances to Affiliates, Net 42,382,000us-gaap_IncreaseDecreaseInNotesReceivableRelatedParties
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
61,114,000us-gaap_IncreaseDecreaseInNotesReceivableRelatedParties
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(21,263,000)us-gaap_IncreaseDecreaseInNotesReceivableRelatedParties
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Purchases of Investment Securities (1,086,437,000)us-gaap_PaymentsToAcquireInvestments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(909,998,000)us-gaap_PaymentsToAcquireInvestments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(1,045,422,000)us-gaap_PaymentsToAcquireInvestments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Sales of Investment Securities 1,031,793,000us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
858,406,000us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
987,550,000us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Acquisitions of Nuclear Fuel (116,168,000)us-gaap_PaymentsForNuclearFuel
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(153,730,000)us-gaap_PaymentsForNuclearFuel
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(106,714,000)us-gaap_PaymentsForNuclearFuel
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Insurance Proceeds Related to Cook Plant Fire 0us-gaap_ProceedsFromInsuranceSettlementInvestingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
72,000,000us-gaap_ProceedsFromInsuranceSettlementInvestingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
0us-gaap_ProceedsFromInsuranceSettlementInvestingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Other Investing Activities 10,498,000us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
32,635,000us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
29,324,000us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Net Cash Flows from (Used for) Investing Activities (602,653,000)us-gaap_NetCashProvidedByUsedInInvestingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(548,430,000)us-gaap_NetCashProvidedByUsedInInvestingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(473,809,000)us-gaap_NetCashProvidedByUsedInInvestingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Financing Activities      
Issuance of Long-term Debt 205,616,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
348,874,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
217,900,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Change in Advances from Affiliates, Net 142,501,000us-gaap_IncreaseDecreaseInNotesPayableRelatedParties
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
0us-gaap_IncreaseDecreaseInNotesPayableRelatedParties
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
0us-gaap_IncreaseDecreaseInNotesPayableRelatedParties
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Retirement of Long-term Debt (218,516,000)us-gaap_RepaymentsOfLongTermDebt
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(370,338,000)us-gaap_RepaymentsOfLongTermDebt
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(220,212,000)us-gaap_RepaymentsOfLongTermDebt
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Proceeds from Nuclear Fuel Sale/Leaseback 0us-gaap_SaleLeasebackTransactionGrossProceedsFinancingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
110,200,000us-gaap_SaleLeasebackTransactionGrossProceedsFinancingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
0us-gaap_SaleLeasebackTransactionGrossProceedsFinancingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Principal Payments for Capital Lease Obligations (48,164,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(8,030,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(6,536,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Dividends Paid on Common Stock (125,000,000)us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(72,500,000)us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(75,000,000)us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Other Financing Activities 649,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
906,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
281,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Net Cash Flows from (Used for) Financing Activities (42,914,000)us-gaap_NetCashProvidedByUsedInFinancingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
9,112,000us-gaap_NetCashProvidedByUsedInFinancingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(83,567,000)us-gaap_NetCashProvidedByUsedInFinancingActivities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Net Increase (Decrease) in Cash and Cash Equivalents (297,000)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(245,000)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
542,000us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Cash and Cash Equivalents at Beginning of Period 1,317,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
1,562,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
1,020,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Cash and Cash Equivalents at End of Period 1,020,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
1,317,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
1,562,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Supplementary Information      
Cash Paid for Interest, Net of Capitalized Amounts 81,580,000us-gaap_InterestPaidNet
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
90,079,000us-gaap_InterestPaidNet
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
98,130,000us-gaap_InterestPaidNet
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Net Cash Paid (Received) for Income Taxes (10,204,000)us-gaap_IncomeTaxesPaidNet
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(31,271,000)us-gaap_IncomeTaxesPaidNet
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
(21,196,000)us-gaap_IncomeTaxesPaidNet
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Noncash Acquisitions Under Capital Leases 16,434,000us-gaap_CapitalLeaseObligationsIncurred
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
114,077,000us-gaap_CapitalLeaseObligationsIncurred
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
6,243,000us-gaap_CapitalLeaseObligationsIncurred
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Construction Expenditures Included in Current Liabilities as of December 31, 66,114,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
85,423,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
112,622,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Acquisition of Nuclear Fuel Included in Current Liabilities as of December 31, 44,529,000aep_AcquisitionOfNuclearFuelIncludedInCurrentLiabilities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
35,000aep_AcquisitionOfNuclearFuelIncludedInCurrentLiabilities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
35,493,000aep_AcquisitionOfNuclearFuelIncludedInCurrentLiabilities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Expected Reimbursement For Spent Nuclear Fuel Dry Cask Storage 3,392,000aep_ExpectedReimbursementForSpentNuclearFuelDryCaskStorage
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
4,352,000aep_ExpectedReimbursementForSpentNuclearFuelDryCaskStorage
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
30,332,000aep_ExpectedReimbursementForSpentNuclearFuelDryCaskStorage
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Ohio Power Co [Member]      
Operating Activites      
Net Income (Loss) 216,422,000us-gaap_ProfitLoss
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
409,980,000us-gaap_ProfitLoss
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
343,534,000us-gaap_ProfitLoss
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:      
Depreciation and Amortization 213,669,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
382,570,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
511,070,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Amortization of Generation Deferrals 110,942,000aep_AmortizationOfGenerationDeferrals
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
0aep_AmortizationOfGenerationDeferrals
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
0aep_AmortizationOfGenerationDeferrals
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Deferred Income Taxes 74,391,000us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
134,463,000us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
45,685,000us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Asset Impairments and Other Related Charges 0us-gaap_OtherAssetImpairmentCharges
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
154,304,000us-gaap_OtherAssetImpairmentCharges
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
287,031,000us-gaap_OtherAssetImpairmentCharges
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Carrying Costs Income (26,546,000)aep_CarryingCostsIncome
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(16,312,000)aep_CarryingCostsIncome
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(16,942,000)aep_CarryingCostsIncome
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Amortization (Deferral) of Storm Costs 0aep_DeferralOfStormCosts
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(1,822,000)aep_DeferralOfStormCosts
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(53,453,000)aep_DeferralOfStormCosts
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Allowance for Equity Funds Used During Construction (6,913,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(4,961,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(3,492,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Mark-to-Market of Risk Management Contracts (44,469,000)us-gaap_UnrealizedGainLossOnDerivatives
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
17,597,000us-gaap_UnrealizedGainLossOnDerivatives
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
12,143,000us-gaap_UnrealizedGainLossOnDerivatives
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Pension Contributions to Qualified Plan Trust (6,547,000)us-gaap_PensionContributions
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
0us-gaap_PensionContributions
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(43,189,000)us-gaap_PensionContributions
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Property Taxes (4,589,000)us-gaap_AmortizationOfDeferredPropertyTaxes
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(11,760,000)us-gaap_AmortizationOfDeferredPropertyTaxes
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(3,849,000)us-gaap_AmortizationOfDeferredPropertyTaxes
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Fuel Over/Under-Recovery, Net 62,093,000aep_FuelOverUnderRecoveryNet
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
36,165,000aep_FuelOverUnderRecoveryNet
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
10,598,000aep_FuelOverUnderRecoveryNet
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Deferral of Ohio Capacity Costs, Net (156,986,000)aep_DeferralOfOhioCapacityCosts
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(214,384,000)aep_DeferralOfOhioCapacityCosts
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(65,274,000)aep_DeferralOfOhioCapacityCosts
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Change in Regulatory Assets 115,658,000aep_ChangeInRegulatoryAssets
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(14,362,000)aep_ChangeInRegulatoryAssets
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(72,879,000)aep_ChangeInRegulatoryAssets
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Change in Other Noncurrent Assets (38,407,000)us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
46,042,000us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
69,229,000us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Change in Other Noncurrent Liabilities 94,136,000us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(52,809,000)us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(27,039,000)us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Changes in Certain Components of Working Capital:      
Accounts Receivable, Net (29,788,000)us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
86,640,000us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(37,787,000)us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Fuel, Materials and Supplies (7,198,000)us-gaap_IncreaseDecreaseInInventories
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
80,250,000us-gaap_IncreaseDecreaseInInventories
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(54,945,000)us-gaap_IncreaseDecreaseInInventories
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Accounts Payable (30,338,000)us-gaap_IncreaseDecreaseInAccountsPayable
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(2,919,000)us-gaap_IncreaseDecreaseInAccountsPayable
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(63,450,000)us-gaap_IncreaseDecreaseInAccountsPayable
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Customer Deposits 4,782,000us-gaap_IncreaseDecreaseInCustomerDeposits
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(784,000)us-gaap_IncreaseDecreaseInCustomerDeposits
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(4,821,000)us-gaap_IncreaseDecreaseInCustomerDeposits
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Accrued Taxes, Net (7,212,000)us-gaap_IncreaseDecreaseInAccruedTaxesPayable
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
23,839,000us-gaap_IncreaseDecreaseInAccruedTaxesPayable
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
41,475,000us-gaap_IncreaseDecreaseInAccruedTaxesPayable
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Other Current Assets 1,568,000us-gaap_IncreaseDecreaseInOtherCurrentAssets
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
7,804,000us-gaap_IncreaseDecreaseInOtherCurrentAssets
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
9,977,000us-gaap_IncreaseDecreaseInOtherCurrentAssets
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Other Current Liabilities 22,923,000us-gaap_IncreaseDecreaseInOtherCurrentLiabilities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(59,512,000)us-gaap_IncreaseDecreaseInOtherCurrentLiabilities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
22,490,000us-gaap_IncreaseDecreaseInOtherCurrentLiabilities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Net Cash Flows from (Used for) Operating Activities 557,591,000us-gaap_NetCashProvidedByUsedInOperatingActivities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
1,000,029,000us-gaap_NetCashProvidedByUsedInOperatingActivities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
906,112,000us-gaap_NetCashProvidedByUsedInOperatingActivities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Investing Activities      
Construction Expenditures (453,474,000)us-gaap_PaymentsForConstructionInProcess
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(640,050,000)us-gaap_PaymentsForConstructionInProcess
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(517,744,000)us-gaap_PaymentsForConstructionInProcess
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Change in Restricted Cash for Securitized Funding (9,300,000)us-gaap_IncreaseDecreaseInRestrictedCash
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(19,387,000)us-gaap_IncreaseDecreaseInRestrictedCash
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
0us-gaap_IncreaseDecreaseInRestrictedCash
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Change in Advances to Affiliates, Net 26,597,000us-gaap_IncreaseDecreaseInNotesReceivableRelatedParties
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
4,330,000us-gaap_IncreaseDecreaseInNotesReceivableRelatedParties
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
103,036,000us-gaap_IncreaseDecreaseInNotesReceivableRelatedParties
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Acquisitions of Assets (3,519,000)us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(4,166,000)us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(2,915,000)us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Proceeds from Sales of Assets 1,212,000us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
62,975,000us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
7,320,000us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Proceeds from Notes Receivable - Affiliated 178,580,000aep_ProceedsFromNotesReceivableAffiliated
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
0aep_ProceedsFromNotesReceivableAffiliated
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
0aep_ProceedsFromNotesReceivableAffiliated
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Other Investing Activities 4,831,000us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
2,370,000us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
10,014,000us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Net Cash Flows from (Used for) Investing Activities (255,073,000)us-gaap_NetCashProvidedByUsedInInvestingActivities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(593,928,000)us-gaap_NetCashProvidedByUsedInInvestingActivities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(400,289,000)us-gaap_NetCashProvidedByUsedInInvestingActivities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Financing Activities      
Capital Contributions from Parent 175,000,000us-gaap_ProceedsFromContributionsFromParent
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
0us-gaap_ProceedsFromContributionsFromParent
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
0us-gaap_ProceedsFromContributionsFromParent
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Issuance of Long-term Debt 0us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
1,378,326,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
0us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Issuance of Long-term Debt - Affiliated 0us-gaap_ProceedsFromRelatedPartyDebt
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
200,000,000us-gaap_ProceedsFromRelatedPartyDebt
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
0us-gaap_ProceedsFromRelatedPartyDebt
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Change in Advances from Affiliates, Net 0us-gaap_IncreaseDecreaseInNotesPayableRelatedParties
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
1,143,000us-gaap_IncreaseDecreaseInNotesPayableRelatedParties
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
0us-gaap_IncreaseDecreaseInNotesPayableRelatedParties
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Retirement of Long-term Debt (438,601,000)us-gaap_RepaymentsOfLongTermDebt
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(1,196,032,000)us-gaap_RepaymentsOfLongTermDebt
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(194,500,000)us-gaap_RepaymentsOfLongTermDebt
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Retirement of Long-term Debt - Affiliated 0us-gaap_RepaymentsOfRelatedPartyDebt
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(400,000,000)us-gaap_RepaymentsOfRelatedPartyDebt
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
0us-gaap_RepaymentsOfRelatedPartyDebt
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Principal Payments for Capital Lease Obligations (5,092,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(17,199,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(10,072,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Dividends Paid on Common Stock (35,000,000)us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(375,000,000)us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(300,000,000)us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Other Financing Activities 1,041,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
2,025,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
294,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Net Cash Flows from (Used for) Financing Activities (302,652,000)us-gaap_NetCashProvidedByUsedInFinancingActivities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(406,737,000)us-gaap_NetCashProvidedByUsedInFinancingActivities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(504,278,000)us-gaap_NetCashProvidedByUsedInFinancingActivities
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Net Increase (Decrease) in Cash and Cash Equivalents (134,000)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(636,000)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
1,545,000us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Cash and Cash Equivalents at Beginning of Period 3,004,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
3,640,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
2,095,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Cash and Cash Equivalents at End of Period 2,870,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
3,004,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
3,640,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Supplementary Information      
Cash Paid for Interest, Net of Capitalized Amounts 132,380,000us-gaap_InterestPaidNet
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
195,677,000us-gaap_InterestPaidNet
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
212,753,000us-gaap_InterestPaidNet
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Net Cash Paid (Received) for Income Taxes 44,036,000us-gaap_IncomeTaxesPaidNet
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
93,324,000us-gaap_IncomeTaxesPaidNet
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
69,771,000us-gaap_IncomeTaxesPaidNet
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Noncash Acquisitions Under Capital Leases 4,842,000us-gaap_CapitalLeaseObligationsIncurred
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
7,655,000us-gaap_CapitalLeaseObligationsIncurred
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
8,602,000us-gaap_CapitalLeaseObligationsIncurred
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Government Grants Included in Accounts Receivable as of December 31, 0aep_GovernmentGrantsIncludedInAccountsReceivable
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
300,000aep_GovernmentGrantsIncludedInAccountsReceivable
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
660,000aep_GovernmentGrantsIncludedInAccountsReceivable
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Construction Expenditures Included in Current Liabilities as of December 31, 43,350,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
92,324,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
84,321,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Noncash Distribution of Cook Coal Terminal to Parent 0aep_NoncashDistributionOfCookCoalTerminalToParent
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(22,303,000)aep_NoncashDistributionOfCookCoalTerminalToParent
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
0aep_NoncashDistributionOfCookCoalTerminalToParent
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Noncash Distribution of OPCo Generation to Parent 0aep_NoncashDistributionOfOPCoGenerationToParent
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
(3,080,954,000)aep_NoncashDistributionOfOPCoGenerationToParent
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
0aep_NoncashDistributionOfOPCoGenerationToParent
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Public Service Co Of Oklahoma [Member]      
Operating Activites      
Net Income (Loss) 86,929,000us-gaap_ProfitLoss
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
97,796,000us-gaap_ProfitLoss
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
114,141,000us-gaap_ProfitLoss
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:      
Depreciation and Amortization 100,977,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
95,667,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
95,180,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Deferred Income Taxes 74,756,000us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
53,788,000us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
48,916,000us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Carrying Costs Income 0aep_CarryingCostsIncome
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(338,000)aep_CarryingCostsIncome
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(1,856,000)aep_CarryingCostsIncome
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Allowance for Equity Funds Used During Construction (3,071,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(4,187,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(2,007,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Mark-to-Market of Risk Management Contracts 1,916,000us-gaap_UnrealizedGainLossOnDerivatives
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(6,362,000)us-gaap_UnrealizedGainLossOnDerivatives
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
3,740,000us-gaap_UnrealizedGainLossOnDerivatives
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Pension Contributions to Qualified Plan Trust (4,439,000)us-gaap_PensionContributions
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
0us-gaap_PensionContributions
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(12,306,000)us-gaap_PensionContributions
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Fuel Over/Under-Recovery, Net (32,401,000)aep_FuelOverUnderRecoveryNet
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(12,643,000)aep_FuelOverUnderRecoveryNet
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
12,258,000aep_FuelOverUnderRecoveryNet
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Change in Other Noncurrent Assets (5,228,000)us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(16,435,000)us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
7,436,000us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Change in Other Noncurrent Liabilities (4,545,000)us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(15,271,000)us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
4,762,000us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Changes in Certain Components of Working Capital:      
Accounts Receivable, Net 8,905,000us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(4,376,000)us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
4,422,000us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Fuel, Materials and Supplies 582,000us-gaap_IncreaseDecreaseInInventories
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
6,370,000us-gaap_IncreaseDecreaseInInventories
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(3,067,000)us-gaap_IncreaseDecreaseInInventories
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Accounts Payable (26,336,000)us-gaap_IncreaseDecreaseInAccountsPayable
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
37,248,000us-gaap_IncreaseDecreaseInAccountsPayable
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
3,158,000us-gaap_IncreaseDecreaseInAccountsPayable
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Accrued Taxes, Net (5,562,000)us-gaap_IncreaseDecreaseInAccruedTaxesPayable
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
332,000us-gaap_IncreaseDecreaseInAccruedTaxesPayable
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
5,006,000us-gaap_IncreaseDecreaseInAccruedTaxesPayable
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Other Current Assets (843,000)us-gaap_IncreaseDecreaseInOtherCurrentAssets
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
1,450,000us-gaap_IncreaseDecreaseInOtherCurrentAssets
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(970,000)us-gaap_IncreaseDecreaseInOtherCurrentAssets
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Other Current Liabilities 17,830,000us-gaap_IncreaseDecreaseInOtherCurrentLiabilities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
5,877,000us-gaap_IncreaseDecreaseInOtherCurrentLiabilities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
5,538,000us-gaap_IncreaseDecreaseInOtherCurrentLiabilities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Net Cash Flows from (Used for) Operating Activities 209,470,000us-gaap_NetCashProvidedByUsedInOperatingActivities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
238,916,000us-gaap_NetCashProvidedByUsedInOperatingActivities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
284,351,000us-gaap_NetCashProvidedByUsedInOperatingActivities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Investing Activities      
Construction Expenditures (367,490,000)us-gaap_PaymentsForConstructionInProcess
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(259,449,000)us-gaap_PaymentsForConstructionInProcess
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(224,295,000)us-gaap_PaymentsForConstructionInProcess
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Change in Advances to Affiliates, Net 0us-gaap_IncreaseDecreaseInNotesReceivableRelatedParties
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
10,558,000us-gaap_IncreaseDecreaseInNotesReceivableRelatedParties
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
29,318,000us-gaap_IncreaseDecreaseInNotesReceivableRelatedParties
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Other Investing Activities 2,784,000us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(2,059,000)us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
1,723,000us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Net Cash Flows from (Used for) Investing Activities (364,706,000)us-gaap_NetCashProvidedByUsedInInvestingActivities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(250,950,000)us-gaap_NetCashProvidedByUsedInInvestingActivities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(193,254,000)us-gaap_NetCashProvidedByUsedInInvestingActivities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Financing Activities      
Issuance of Long-term Debt 74,973,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
49,709,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
2,395,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Change in Advances from Affiliates, Net 117,477,000us-gaap_IncreaseDecreaseInNotesPayableRelatedParties
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
36,772,000us-gaap_IncreaseDecreaseInNotesPayableRelatedParties
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
0us-gaap_IncreaseDecreaseInNotesPayableRelatedParties
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Retirement of Long-term Debt (34,115,000)us-gaap_RepaymentsOfLongTermDebt
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(402,000)us-gaap_RepaymentsOfLongTermDebt
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(229,000)us-gaap_RepaymentsOfLongTermDebt
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Principal Payments for Capital Lease Obligations (3,653,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(3,498,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(3,481,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Dividends Paid on Common Stock 0us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(71,250,000)us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(90,000,000)us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Other Financing Activities 629,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
613,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
172,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Net Cash Flows from (Used for) Financing Activities 155,311,000us-gaap_NetCashProvidedByUsedInFinancingActivities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
11,944,000us-gaap_NetCashProvidedByUsedInFinancingActivities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(91,143,000)us-gaap_NetCashProvidedByUsedInFinancingActivities
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Net Increase (Decrease) in Cash and Cash Equivalents 75,000us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(90,000)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
(46,000)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Cash and Cash Equivalents at Beginning of Period 1,277,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
1,367,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
1,413,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Cash and Cash Equivalents at End of Period 1,352,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
1,277,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
1,367,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Supplementary Information      
Cash Paid for Interest, Net of Capitalized Amounts 52,766,000us-gaap_InterestPaidNet
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
51,387,000us-gaap_InterestPaidNet
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
52,403,000us-gaap_InterestPaidNet
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Net Cash Paid (Received) for Income Taxes (21,150,000)us-gaap_IncomeTaxesPaidNet
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
8,671,000us-gaap_IncomeTaxesPaidNet
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
27,229,000us-gaap_IncomeTaxesPaidNet
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Noncash Acquisitions Under Capital Leases 2,262,000us-gaap_CapitalLeaseObligationsIncurred
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
5,795,000us-gaap_CapitalLeaseObligationsIncurred
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
1,542,000us-gaap_CapitalLeaseObligationsIncurred
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Construction Expenditures Included in Current Liabilities as of December 31, 38,581,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
63,648,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
27,118,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Southwestern Electric Power Co [Member]      
Operating Activites      
Net Income (Loss) 144,559,000us-gaap_ProfitLoss
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
153,819,000us-gaap_ProfitLoss
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
202,513,000us-gaap_ProfitLoss
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:      
Depreciation and Amortization 185,134,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
179,251,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
138,778,000us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Deferred Income Taxes 239,426,000us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
81,888,000us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
260,761,000us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Asset Impairments and Other Related Charges 0us-gaap_OtherAssetImpairmentCharges
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
0us-gaap_OtherAssetImpairmentCharges
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
13,000,000us-gaap_OtherAssetImpairmentCharges
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Allowance for Equity Funds Used During Construction (11,947,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(7,338,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(57,054,000)us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Mark-to-Market of Risk Management Contracts 2,133,000us-gaap_UnrealizedGainLossOnDerivatives
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(1,539,000)us-gaap_UnrealizedGainLossOnDerivatives
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(4,159,000)us-gaap_UnrealizedGainLossOnDerivatives
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Pension Contributions to Qualified Plan Trust (3,832,000)us-gaap_PensionContributions
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
0us-gaap_PensionContributions
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(13,192,000)us-gaap_PensionContributions
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Fuel Over/Under-Recovery, Net (13,350,000)aep_FuelOverUnderRecoveryNet
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(18,916,000)aep_FuelOverUnderRecoveryNet
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
14,045,000aep_FuelOverUnderRecoveryNet
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Change in Regulatory Liabilities (24,559,000)aep_ChangeInRegulatoryLiabilities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(12,806,000)aep_ChangeInRegulatoryLiabilities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
37,955,000aep_ChangeInRegulatoryLiabilities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Change in Other Noncurrent Assets (2,080,000)us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
34,559,000us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
21,309,000us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Change in Other Noncurrent Liabilities 23,590,000us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(634,000)us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
14,594,000us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Changes in Certain Components of Working Capital:      
Accounts Receivable, Net 25,448,000us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(35,472,000)us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(21,919,000)us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Fuel, Materials and Supplies 6,267,000us-gaap_IncreaseDecreaseInInventories
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
6,558,000us-gaap_IncreaseDecreaseInInventories
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(46,106,000)us-gaap_IncreaseDecreaseInInventories
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Accounts Payable 4,359,000us-gaap_IncreaseDecreaseInAccountsPayable
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
12,816,000us-gaap_IncreaseDecreaseInAccountsPayable
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
3,813,000us-gaap_IncreaseDecreaseInAccountsPayable
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Accrued Taxes, Net (12,802,000)us-gaap_IncreaseDecreaseInAccruedTaxesPayable
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
25,341,000us-gaap_IncreaseDecreaseInAccruedTaxesPayable
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(16,057,000)us-gaap_IncreaseDecreaseInAccruedTaxesPayable
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Other Current Assets (4,356,000)us-gaap_IncreaseDecreaseInOtherCurrentAssets
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(1,398,000)us-gaap_IncreaseDecreaseInOtherCurrentAssets
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(387,000)us-gaap_IncreaseDecreaseInOtherCurrentAssets
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Other Current Liabilities 21,193,000us-gaap_IncreaseDecreaseInOtherCurrentLiabilities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
1,634,000us-gaap_IncreaseDecreaseInOtherCurrentLiabilities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(3,611,000)us-gaap_IncreaseDecreaseInOtherCurrentLiabilities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Net Cash Flows from (Used for) Operating Activities 579,183,000us-gaap_NetCashProvidedByUsedInOperatingActivities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
417,763,000us-gaap_NetCashProvidedByUsedInOperatingActivities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
544,283,000us-gaap_NetCashProvidedByUsedInOperatingActivities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Investing Activities      
Construction Expenditures (511,388,000)us-gaap_PaymentsForConstructionInProcess
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(411,512,000)us-gaap_PaymentsForConstructionInProcess
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(542,427,000)us-gaap_PaymentsForConstructionInProcess
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Change in Advances to Affiliates, Net (41,033,000)us-gaap_IncreaseDecreaseInNotesReceivableRelatedParties
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
153,829,000us-gaap_IncreaseDecreaseInNotesReceivableRelatedParties
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(153,829,000)us-gaap_IncreaseDecreaseInNotesReceivableRelatedParties
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Other Investing Activities 5,080,000us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(2,074,000)us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
1,605,000us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Net Cash Flows from (Used for) Investing Activities (547,341,000)us-gaap_NetCashProvidedByUsedInInvestingActivities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(259,757,000)us-gaap_NetCashProvidedByUsedInInvestingActivities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(694,651,000)us-gaap_NetCashProvidedByUsedInInvestingActivities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Financing Activities      
Issuance of Long-term Debt 99,415,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
0us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
336,418,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Credit Facility Borrowings 0us-gaap_ProceedsFromShortTermDebtMaturingInMoreThanThreeMonths
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
17,091,000us-gaap_ProceedsFromShortTermDebtMaturingInMoreThanThreeMonths
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
25,123,000us-gaap_ProceedsFromShortTermDebtMaturingInMoreThanThreeMonths
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Change in Advances from Affiliates, Net (9,180,000)us-gaap_IncreaseDecreaseInNotesPayableRelatedParties
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
9,180,000us-gaap_IncreaseDecreaseInNotesPayableRelatedParties
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(132,473,000)us-gaap_IncreaseDecreaseInNotesPayableRelatedParties
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Retirement of Long-term Debt (3,250,000)us-gaap_RepaymentsOfLongTermDebt
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(3,250,000)us-gaap_RepaymentsOfLongTermDebt
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(21,625,000)us-gaap_RepaymentsOfLongTermDebt
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Credit Facility Repayments 0us-gaap_RepaymentsOfShortTermDebtMaturingInMoreThanThreeMonths
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(19,694,000)us-gaap_RepaymentsOfShortTermDebtMaturingInMoreThanThreeMonths
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(39,536,000)us-gaap_RepaymentsOfShortTermDebtMaturingInMoreThanThreeMonths
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Principal Payments for Capital Lease Obligations (18,318,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(18,111,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(16,537,000)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Dividends Paid on Common Stock (100,000,000)us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(125,000,000)us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
0us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Dividends Paid on Common Stock (4,253,000)us-gaap_PaymentsOfDividendsCommonStock
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(3,791,000)us-gaap_PaymentsOfDividendsCommonStock
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(3,752,000)us-gaap_PaymentsOfDividendsCommonStock
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Other Financing Activities 859,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
774,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
3,985,000us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Net Cash Flows from (Used for) Financing Activities (34,727,000)us-gaap_NetCashProvidedByUsedInFinancingActivities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(142,801,000)us-gaap_NetCashProvidedByUsedInFinancingActivities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
151,603,000us-gaap_NetCashProvidedByUsedInFinancingActivities
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Net Increase (Decrease) in Cash and Cash Equivalents (2,885,000)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
15,205,000us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
1,235,000us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Cash and Cash Equivalents at Beginning of Period 17,241,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
2,036,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
801,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Cash and Cash Equivalents at End of Period 14,356,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
17,241,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
2,036,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Supplementary Information      
Cash Paid for Interest, Net of Capitalized Amounts 116,855,000us-gaap_InterestPaidNet
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
120,427,000us-gaap_InterestPaidNet
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
68,918,000us-gaap_InterestPaidNet
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Net Cash Paid (Received) for Income Taxes (152,213,000)us-gaap_IncomeTaxesPaidNet
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(35,363,000)us-gaap_IncomeTaxesPaidNet
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
(191,638,000)us-gaap_IncomeTaxesPaidNet
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Noncash Acquisitions Under Capital Leases 4,130,000us-gaap_CapitalLeaseObligationsIncurred
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
9,376,000us-gaap_CapitalLeaseObligationsIncurred
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
20,547,000us-gaap_CapitalLeaseObligationsIncurred
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Construction Expenditures Included in Current Liabilities as of December 31, $ 94,263,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
$ 63,169,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
$ 55,767,000us-gaap_ConstructionInProgressExpendituresIncurredButNotYetPaid
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember