XML 48 R48.htm IDEA: XBRL DOCUMENT v2.4.1.9
Fair Value Long-term Debt, Other Temporary Investments, Nuclear Trusts (Details) (USD $)
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Book Values and Fair Values of Long - term Debt      
Total Long-term Debt Outstanding $ 19,229,000,000us-gaap_LongTermDebt   $ 18,684,000,000us-gaap_LongTermDebt
Long Term Debt, Fair Value 22,015,000,000us-gaap_LongTermDebtFairValue   21,075,000,000us-gaap_LongTermDebtFairValue
Other Temporary Investments      
Cost 280,000,000us-gaap_InvestmentOwnedAtCost   374,000,000us-gaap_InvestmentOwnedAtCost
Gross Unrealized Gains 13,000,000us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciation   12,000,000us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciation
Gross Unrealized Losses 0us-gaap_InvestmentOwnedUnrecognizedUnrealizedDepreciation   0us-gaap_InvestmentOwnedUnrecognizedUnrealizedDepreciation
Estimated Fair Value 293,000,000us-gaap_ShortTermInvestments   386,000,000us-gaap_ShortTermInvestments
Debt and Equity Securities Within Other Temporary Investments [Abstract]      
Proceeds from Investment Sales 0us-gaap_ProceedsFromSaleOfShortTermInvestments 0us-gaap_ProceedsFromSaleOfShortTermInvestments  
Purchases of Investments 0us-gaap_PaymentsToAcquireShortTermInvestments 1,000,000us-gaap_PaymentsToAcquireShortTermInvestments  
Gross Realized Gains on Investment Sales 0aep_GrossRealizedGainsOnInvestmentSalesOnShortTermInvestment 0aep_GrossRealizedGainsOnInvestmentSalesOnShortTermInvestment  
Gross Realized Losses on Investment Sales 0aep_GrossRealizedLossesOnInvestmentSalesOnShortTermInvestment 0aep_GrossRealizedLossesOnInvestmentSalesOnShortTermInvestment  
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 2,122,000,000aep_SpentNuclearFuelAndDecommissioningTrusts   2,096,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
Gross Unrealized Gains 658,000,000aep_GrossUnrealizedGains   649,000,000aep_GrossUnrealizedGains
Other-Than-Temporary Impairments (83,000,000)aep_TemporaryImpairments   (85,000,000)aep_TemporaryImpairments
Securities Activity Within Decommissioning and SNF Trusts [Abstract]      
Proceeds from Investment Sales 228,000,000aep_ProceedsFromInvestmentSales 148,000,000aep_ProceedsFromInvestmentSales  
Purchases of Investments 246,000,000aep_PurchasesOfInvestments 164,000,000aep_PurchasesOfInvestments  
Gross Realized Gains on Investment Sales 11,000,000aep_GrossRealizedGainsOnInvestmentSales 8,000,000aep_GrossRealizedGainsOnInvestmentSales  
Gross Realized Losses on Investment Sales 4,000,000aep_GrossRealizedLossesOnInvestmentSales 1,000,000aep_GrossRealizedLossesOnInvestmentSales  
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 2,122,000,000aep_SpentNuclearFuelAndDecommissioningTrusts   2,096,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
Fair Value Measurements (Textuals) [Abstract]      
Adjusted Cost of Debt Securities 899,000,000aep_AdjustedCostOfDebtSecurities   903,000,000aep_AdjustedCostOfDebtSecurities
Adjusted Cost of Domestic Equity Securities 534,000,000aep_AdjustedCostOfEquitySecurities   524,000,000aep_AdjustedCostOfEquitySecurities
Appalachian Power Co [Member]      
Book Values and Fair Values of Long - term Debt      
Total Long-term Debt Outstanding 3,969,405,000us-gaap_LongTermDebt
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember		   3,980,274,000us-gaap_LongTermDebt
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Long Term Debt, Fair Value 4,815,530,000us-gaap_LongTermDebtFairValue
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember		   4,711,210,000us-gaap_LongTermDebtFairValue
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Other Temporary Investments      
Cash 7,884,000us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember		   15,599,000us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_AppalachianPowerCoMember
Indiana Michigan Power Co [Member]      
Book Values and Fair Values of Long - term Debt      
Total Long-term Debt Outstanding 2,001,609,000us-gaap_LongTermDebt
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		   2,027,397,000us-gaap_LongTermDebt
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Long Term Debt, Fair Value 2,260,547,000us-gaap_LongTermDebtFairValue
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		   2,255,124,000us-gaap_LongTermDebtFairValue
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 2,122,387,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		   2,095,732,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Gross Unrealized Gains 658,306,000aep_GrossUnrealizedGains
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		   649,132,000aep_GrossUnrealizedGains
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Other-Than-Temporary Impairments (82,903,000)aep_TemporaryImpairments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		   (85,495,000)aep_TemporaryImpairments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Securities Activity Within Decommissioning and SNF Trusts [Abstract]      
Proceeds from Investment Sales 228,164,000aep_ProceedsFromInvestmentSales
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		 147,700,000aep_ProceedsFromInvestmentSales
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		  
Purchases of Investments 245,841,000aep_PurchasesOfInvestments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		 164,511,000aep_PurchasesOfInvestments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		  
Gross Realized Gains on Investment Sales 11,153,000aep_GrossRealizedGainsOnInvestmentSales
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		 8,141,000aep_GrossRealizedGainsOnInvestmentSales
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		  
Gross Realized Losses on Investment Sales 3,771,000aep_GrossRealizedLossesOnInvestmentSales
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		 874,000aep_GrossRealizedLossesOnInvestmentSales
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		  
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 2,122,387,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		   2,095,732,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Fair Value Measurements (Textuals) [Abstract]      
Adjusted Cost of Debt Securities 899,000,000aep_AdjustedCostOfDebtSecurities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		   903,000,000aep_AdjustedCostOfDebtSecurities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Adjusted Cost of Domestic Equity Securities 534,000,000aep_AdjustedCostOfEquitySecurities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		   524,000,000aep_AdjustedCostOfEquitySecurities
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
Ohio Power Co [Member]      
Book Values and Fair Values of Long - term Debt      
Total Long-term Debt Outstanding 2,275,041,000us-gaap_LongTermDebt
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember		   2,297,123,000us-gaap_LongTermDebt
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Long Term Debt, Fair Value 2,735,382,000us-gaap_LongTermDebtFairValue
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember		   2,709,452,000us-gaap_LongTermDebtFairValue
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Other Temporary Investments      
Cash 17,125,000us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember		   28,687,000us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue
/ dei_LegalEntityAxis
= aep_OhioPowerCoMember
Public Service Co Of Oklahoma [Member]      
Book Values and Fair Values of Long - term Debt      
Total Long-term Debt Outstanding 1,291,015,000us-gaap_LongTermDebt
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember		   1,041,036,000us-gaap_LongTermDebt
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Long Term Debt, Fair Value 1,501,358,000us-gaap_LongTermDebtFairValue
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember		   1,216,205,000us-gaap_LongTermDebtFairValue
/ dei_LegalEntityAxis
= aep_PublicServiceCoOfOklahomaMember
Southwestern Electric Power Co [Member]      
Book Values and Fair Values of Long - term Debt      
Total Long-term Debt Outstanding 2,535,361,000us-gaap_LongTermDebt
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember		   2,140,437,000us-gaap_LongTermDebt
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Long Term Debt, Fair Value 2,827,604,000us-gaap_LongTermDebtFairValue
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember		   2,402,639,000us-gaap_LongTermDebtFairValue
/ dei_LegalEntityAxis
= aep_SouthwesternElectricPowerCoMember
Cash [Member]      
Other Temporary Investments      
Cost 186,000,000us-gaap_InvestmentOwnedAtCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashMember		 [1]   280,000,000us-gaap_InvestmentOwnedAtCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashMember		 [1]
Gross Unrealized Gains 0us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciation
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashMember		 [1]   0us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciation
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashMember		 [1]
Gross Unrealized Losses 0us-gaap_InvestmentOwnedUnrecognizedUnrealizedDepreciation
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashMember		 [1]   0us-gaap_InvestmentOwnedUnrecognizedUnrealizedDepreciation
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashMember		 [1]
Estimated Fair Value 186,000,000us-gaap_ShortTermInvestments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashMember		 [1],[2]   280,000,000us-gaap_ShortTermInvestments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashMember		 [1],[2]
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 31,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashMember		 [3]   20,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashMember		 [3]
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 31,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashMember		 [3]   20,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashMember		 [3]
Cash [Member] | Indiana Michigan Power Co [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 30,731,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashMember		 [4]   19,966,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashMember		 [4]
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 30,731,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashMember		 [4]   19,966,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashMember		 [4]
Fixed Income Funds [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 956,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FixedIncomeFundsMember		   953,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FixedIncomeFundsMember
Gross Unrealized Gains 57,000,000aep_GrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FixedIncomeFundsMember		   50,000,000aep_GrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FixedIncomeFundsMember
Other-Than-Temporary Impairments (5,000,000)aep_TemporaryImpairments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FixedIncomeFundsMember		   (6,000,000)aep_TemporaryImpairments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FixedIncomeFundsMember
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 956,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FixedIncomeFundsMember		   953,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FixedIncomeFundsMember
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 956,047,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FixedIncomeFundsMember		   953,387,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FixedIncomeFundsMember
Gross Unrealized Gains 57,283,000aep_GrossUnrealizedGains
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FixedIncomeFundsMember		   50,344,000aep_GrossUnrealizedGains
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FixedIncomeFundsMember
Other-Than-Temporary Impairments (4,260,000)aep_TemporaryImpairments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FixedIncomeFundsMember		   (6,353,000)aep_TemporaryImpairments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FixedIncomeFundsMember
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 956,047,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FixedIncomeFundsMember		   953,387,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FixedIncomeFundsMember
Mutual Funds Fixed Income [Member]      
Other Temporary Investments      
Cost 81,000,000us-gaap_InvestmentOwnedAtCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_MutualFundsFixedIncomeMember		   81,000,000us-gaap_InvestmentOwnedAtCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_MutualFundsFixedIncomeMember
Gross Unrealized Gains 0us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciation
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_MutualFundsFixedIncomeMember		   0us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciation
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_MutualFundsFixedIncomeMember
Gross Unrealized Losses 0us-gaap_InvestmentOwnedUnrecognizedUnrealizedDepreciation
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_MutualFundsFixedIncomeMember		   0us-gaap_InvestmentOwnedUnrecognizedUnrealizedDepreciation
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_MutualFundsFixedIncomeMember
Estimated Fair Value 81,000,000us-gaap_ShortTermInvestments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_MutualFundsFixedIncomeMember		   81,000,000us-gaap_ShortTermInvestments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_MutualFundsFixedIncomeMember
Domestic [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 1,135,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_DomesticMember		 [5]   1,123,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_DomesticMember		 [5]
Gross Unrealized Gains 601,000,000aep_GrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_DomesticMember		   599,000,000aep_GrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_DomesticMember
Other-Than-Temporary Impairments (78,000,000)aep_TemporaryImpairments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_DomesticMember		   (79,000,000)aep_TemporaryImpairments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_DomesticMember
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 1,135,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_DomesticMember		 [5]   1,123,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_DomesticMember		 [5]
Domestic [Member] | Indiana Michigan Power Co [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 1,135,609,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_DomesticMember		 [5]   1,122,379,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_DomesticMember		 [5]
Gross Unrealized Gains 601,023,000aep_GrossUnrealizedGains
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_DomesticMember		   598,788,000aep_GrossUnrealizedGains
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_DomesticMember
Other-Than-Temporary Impairments (78,643,000)aep_TemporaryImpairments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_DomesticMember		   (79,142,000)aep_TemporaryImpairments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_DomesticMember
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 1,135,609,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_DomesticMember		 [5]   1,122,379,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_DomesticMember		 [5]
Mutual Funds Equity [Member]      
Other Temporary Investments      
Cost 13,000,000us-gaap_InvestmentOwnedAtCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_MutualFundsEquityMember		   13,000,000us-gaap_InvestmentOwnedAtCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_MutualFundsEquityMember
Gross Unrealized Gains 13,000,000us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciation
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_MutualFundsEquityMember		   12,000,000us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciation
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_MutualFundsEquityMember
Gross Unrealized Losses 0us-gaap_InvestmentOwnedUnrecognizedUnrealizedDepreciation
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_MutualFundsEquityMember		   0us-gaap_InvestmentOwnedUnrecognizedUnrealizedDepreciation
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_MutualFundsEquityMember
Estimated Fair Value 26,000,000us-gaap_ShortTermInvestments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_MutualFundsEquityMember		 [5]   25,000,000us-gaap_ShortTermInvestments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= aep_MutualFundsEquityMember		 [5]
Cash and Cash Equivalents [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 31,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashAndCashEquivalentsMember		   20,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashAndCashEquivalentsMember
Gross Unrealized Gains 0aep_GrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashAndCashEquivalentsMember		   0aep_GrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashAndCashEquivalentsMember
Other-Than-Temporary Impairments 0aep_TemporaryImpairments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashAndCashEquivalentsMember		   0aep_TemporaryImpairments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashAndCashEquivalentsMember
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 31,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashAndCashEquivalentsMember		   20,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashAndCashEquivalentsMember
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 30,731,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashAndCashEquivalentsMember		   19,966,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashAndCashEquivalentsMember
Gross Unrealized Gains 0aep_GrossUnrealizedGains
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashAndCashEquivalentsMember		   0aep_GrossUnrealizedGains
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashAndCashEquivalentsMember
Other-Than-Temporary Impairments 0aep_TemporaryImpairments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashAndCashEquivalentsMember		   0aep_TemporaryImpairments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashAndCashEquivalentsMember
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 30,731,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashAndCashEquivalentsMember		   19,966,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CashAndCashEquivalentsMember
US Government Agencies Debt Securities [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 695,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember		   697,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Gross Unrealized Gains 51,000,000aep_GrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember		   45,000,000aep_GrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Other-Than-Temporary Impairments (3,000,000)aep_TemporaryImpairments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember		   (5,000,000)aep_TemporaryImpairments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 695,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember		   697,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 695,576,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember		   697,042,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Gross Unrealized Gains 51,093,000aep_GrossUnrealizedGains
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember		   44,615,000aep_GrossUnrealizedGains
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Other-Than-Temporary Impairments (2,616,000)aep_TemporaryImpairments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember		   (5,016,000)aep_TemporaryImpairments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 695,576,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember		   697,042,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Corporate Debt [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 60,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		   48,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Gross Unrealized Gains 5,000,000aep_GrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		   4,000,000aep_GrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Other-Than-Temporary Impairments (1,000,000)aep_TemporaryImpairments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		   (1,000,000)aep_TemporaryImpairments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 60,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		   48,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Corporate Debt [Member] | Indiana Michigan Power Co [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 59,764,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		   47,792,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Gross Unrealized Gains 5,208,000aep_GrossUnrealizedGains
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		   4,523,000aep_GrossUnrealizedGains
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Other-Than-Temporary Impairments (908,000)aep_TemporaryImpairments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		   (1,018,000)aep_TemporaryImpairments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 59,764,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		   47,792,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
State and Local Jurisdiction [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 201,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_StateAndLocalJurisdictionMember		   208,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_StateAndLocalJurisdictionMember
Gross Unrealized Gains 1,000,000aep_GrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_StateAndLocalJurisdictionMember		   1,000,000aep_GrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_StateAndLocalJurisdictionMember
Other-Than-Temporary Impairments (1,000,000)aep_TemporaryImpairments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_StateAndLocalJurisdictionMember		   0aep_TemporaryImpairments
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_StateAndLocalJurisdictionMember
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 201,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_StateAndLocalJurisdictionMember		   208,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_StateAndLocalJurisdictionMember
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 200,707,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_StateAndLocalJurisdictionMember		   208,553,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_StateAndLocalJurisdictionMember
Gross Unrealized Gains 982,000aep_GrossUnrealizedGains
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_StateAndLocalJurisdictionMember		   1,206,000aep_GrossUnrealizedGains
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_StateAndLocalJurisdictionMember
Other-Than-Temporary Impairments (736,000)aep_TemporaryImpairments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_StateAndLocalJurisdictionMember		   (319,000)aep_TemporaryImpairments
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_StateAndLocalJurisdictionMember
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 200,707,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_StateAndLocalJurisdictionMember		   208,553,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_StateAndLocalJurisdictionMember
Within One Year [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 148,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ aep_ContractualMaturitiesYearAxis
= aep_WithinOneYearMember		    
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 148,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ aep_ContractualMaturitiesYearAxis
= aep_WithinOneYearMember		    
Within One Year [Member] | Indiana Michigan Power Co [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 148,126,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ aep_ContractualMaturitiesYearAxis
= aep_WithinOneYearMember
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		    
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 148,126,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ aep_ContractualMaturitiesYearAxis
= aep_WithinOneYearMember
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		    
One Year To Five Year [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 407,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ aep_ContractualMaturitiesYearAxis
= aep_OneYearToFiveYearMember		    
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 407,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ aep_ContractualMaturitiesYearAxis
= aep_OneYearToFiveYearMember		    
One Year To Five Year [Member] | Indiana Michigan Power Co [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 406,568,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ aep_ContractualMaturitiesYearAxis
= aep_OneYearToFiveYearMember
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		    
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 406,568,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ aep_ContractualMaturitiesYearAxis
= aep_OneYearToFiveYearMember
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		    
Five Year To Ten Year [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 174,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ aep_ContractualMaturitiesYearAxis
= aep_FiveYearToTenYearMember		    
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 174,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ aep_ContractualMaturitiesYearAxis
= aep_FiveYearToTenYearMember		    
Five Year To Ten Year [Member] | Indiana Michigan Power Co [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 173,946,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ aep_ContractualMaturitiesYearAxis
= aep_FiveYearToTenYearMember
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		    
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 173,946,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ aep_ContractualMaturitiesYearAxis
= aep_FiveYearToTenYearMember
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		    
After Ten Year [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 227,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ aep_ContractualMaturitiesYearAxis
= aep_AfterTenYearMember		    
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities 227,000,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ aep_ContractualMaturitiesYearAxis
= aep_AfterTenYearMember		    
After Ten Year [Member] | Indiana Michigan Power Co [Member]      
Nuclear Trust Fund Investments [Abstract]      
Estimated Fair Value 227,407,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ aep_ContractualMaturitiesYearAxis
= aep_AfterTenYearMember
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		    
Contractual Maturities, Fair Value of Debt Securities      
Contractual Maturities, Fair Value of Debt Securities $ 227,407,000aep_SpentNuclearFuelAndDecommissioningTrusts
/ aep_ContractualMaturitiesYearAxis
= aep_AfterTenYearMember
/ dei_LegalEntityAxis
= aep_IndianaMichiganPowerCoMember		    
[1] Primarily represents amounts held for the repayment of debt.
[2] Amounts in ''Other'' column primarily represent cash deposits in bank accounts with financial institutions or with third parties. Level 1 and Level 2 amounts primarily represent investments in money market funds.
[3] Amounts in ''Other'' column primarily represent accrued interest receivables from financial institutions. Level 1 amounts primarily represent investments in money market funds.
[4] Amounts in “Other” column primarily represent accrued interest receivables from financial institutions. Level 1 amounts primarily represent investments in money market funds.
[5] Amounts represent publicly traded equity securities and equity-based mutual funds.