Fair Value Assets and Liabilities (Details) - USD ($)		3 Months Ended
		Mar. 31, 2022		Mar. 31, 2021	Dec. 31, 2021
Other [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		$ 9,500,000			$ 10,000,000.0
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		7,600,000			7,000,000.0
Total Assets		(1,414,200,000)			(667,100,000)
Risk Management Assets
Risk Management Assets		(1,431,300,000)			(684,100,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities		(777,000,000.0)			(424,900,000)
Other Short-term Investments		258,400,000			268,400,000
Spent Nuclear Fuel and Decommissioning Trusts		3,678,400,000			3,867,000,000
Total Assets		4,553,900,000			4,640,500,000
Risk Management Assets		571,500,000			461,400,000
Risk Management Liabilities		430,400,000			305,700,000
Changes in the Fair Value of Net Trading Derivatives and other investments
Beginning Balance		97,300,000		$ 113,300,000
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	[1],[2]	18,200,000		19,800,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	(19,000,000.0)		(21,300,000)
Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income	[3]	19,300,000		3,100,000
Settlements		(51,600,000)		(47,900,000)
Transfers into Level 3	[4],[5]	2,500,000		500,000
Transfers out of Level 3	[5]	2,900,000		(33,000,000.0)
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	7,400,000		7,300,000
Assets and Liabilities Held for Sale related to KPCo	[7]	4,500,000
Ending Balance		81,500,000		41,800,000
Fair Value Measurements 1 (Textuals)
Assets Held for Sale		2,972,600,000			2,919,700,000
Liabilities Held for Sale		1,873,700,000			1,880,900,000
Level 1 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		248,900,000			258,400,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		2,424,600,000			2,619,600,000
Total Assets		2,729,700,000			2,914,200,000
Risk Management Assets
Risk Management Assets		26,100,000			7,400,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		8,000,000.0			5,300,000
Level 2 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		0			0
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,246,200,000			1,240,400,000
Total Assets		2,979,300,000			2,147,900,000
Risk Management Assets
Risk Management Assets		1,717,600,000			892,600,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		1,021,800,000			577,100,000
Level 3 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		0			0
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Total Assets		259,100,000			245,500,000
Risk Management Assets
Risk Management Assets		259,100,000			245,500,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		177,600,000			148,200,000
2022 [Member] | Level 1 [Member]
Fair Value Measurements 1 (Textuals)
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		14,000,000			1,000,000
2022 [Member] | Level 2 [Member]
Fair Value Measurements 1 (Textuals)
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		96,000,000			42,000,000
2022 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals)
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		37,000,000			82,000,000
2023 - 2025 [Member] | Level 1 [Member]
Fair Value Measurements 1 (Textuals)
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		4,000,000			1,000,000
2023 - 2025 [Member] | Level 2 [Member]
Fair Value Measurements 1 (Textuals)
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		188,000,000			109,000,000
2023 - 2025 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals)
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		8,000,000			10,000,000
2026 - 2027 [Member] | Level 2 [Member]
Fair Value Measurements 1 (Textuals)
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		10,000,000			10,000,000
2026 - 2027 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals)
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		13,000,000			9,000,000
2028 - 2033 [Member] | Level 2 [Member]
Fair Value Measurements 1 (Textuals)
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		4,000,000			3,000,000
2028 - 2033 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals)
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		(11,000,000)			(17,000,000)
Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	[8],[9]	(1,391,100,000)	[10]		(642,400,000)	[11]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[12]	(736,800,000)	[10]		(383,200,000)	[11]
Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[8],[9]	52,800,000	[10]		239,800,000	[11]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[12]	345,400,000	[10]		254,700,000	[11]
Fair Value Measurements 1 (Textuals)
Assets Held for Sale		1,400,000			6,000,000
Liabilities Held for Sale					100,000
Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[8],[9]	26,100,000	[10]		7,400,000	[11]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[12]	8,000,000.0	[10]		5,300,000	[11]
Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[8],[9]	1,194,100,000	[10]		648,500,000	[11]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[12]	896,700,000	[10]		485,000,000.0	[11]
Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[8],[9]	223,700,000	[10]		226,300,000	[11]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[12]	177,500,000	[10]		147,600,000	[11]
Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		223,300,000			164,400,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		169,500,000			135,200,000
Energy Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	12.79			10.30
Energy Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	119.45			76.70
Energy Contracts [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13],[14]	42.15			37.11
Natural Gas Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		10,100,000			3,600,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0			0
Natural Gas Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[15]	2.58			3.11
Natural Gas Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[15]	6.01			4.02
Natural Gas Contracts [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[14],[15]	5.05			3.47
FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		25,700,000			77,500,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		8,100,000			13,000,000.0
FTRs [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	(41.14)			(23.93)
FTRs [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	13.46			26.38
FTRs [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13],[14]	(0.08)			0.86
Commodity Hedges [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	[9]	(40,200,000)			(41,700,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9]	(40,200,000)			(41,700,000)
Commodity Hedges [Member]
Risk Management Assets
Risk Management Assets	[9]	514,800,000			220,400,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9]	3,200,000			12,900,000
Commodity Hedges [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[9]	0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9]	0			0
Commodity Hedges [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[9]	519,600,000			242,900,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9]	43,300,000			54,000,000.0
Commodity Hedges [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[9]	35,400,000			19,200,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9]	100,000			600,000
Interest Rate [Member] | Other [Member]
Risk Management Assets
Risk Management Assets		0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0
Interest Rate [Member]
Risk Management Assets
Risk Management Assets		3,900,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		100,000
Interest Rate [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets		0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0
Interest Rate [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets		3,900,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		100,000
Interest Rate [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0
Fair Value Hedges [Member] | Other [Member]
Risk Management Assets
Risk Management Assets					0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0			0
Fair Value Hedges [Member]
Risk Management Assets
Risk Management Assets					1,200,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		81,700,000			38,100,000
Fair Value Hedges [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets					0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0			0
Fair Value Hedges [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets					1,200,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		81,700,000			38,100,000
Fair Value Hedges [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets					0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0			0
Other Investments | Other [Member]
Risk Management Assets
Risk Management Assets	[16]	0			0
Other Investments
Risk Management Assets
Risk Management Assets	[16]	45,600,000			43,700,000
Other Investments | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[16]	30,100,000			28,800,000
Other Investments | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[16]	15,500,000			14,900,000
Other Investments | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[16]	0			0
AEP Texas Inc. [Member] | Other [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0			0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		(1,300,000)			(600,000)
AEP Texas Inc. [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		39,900,000			30,400,000
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		40,100,000			30,400,000
AEP Texas Inc. [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		39,900,000			30,400,000
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		39,900,000			30,400,000
AEP Texas Inc. [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0			0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		1,500,000			600,000
AEP Texas Inc. [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0			0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		0			0
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	[9]	(1,300,000)			(600,000)
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[9]	200,000			0
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[9]	0			0
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[9]	1,500,000			600,000
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[9]	0			0
AEP Transmission Co [Member]
Fair Value Measurements 1 (Textuals)
Assets Held for Sale		169,900,000			167,900,000
Liabilities Held for Sale		27,600,000			27,600,000
Appalachian Power Co [Member] | Other [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0			0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		(4,300,000)			(5,800,000)
Appalachian Power Co [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		10,000,000.0			17,600,000
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		17,000,000.0			59,600,000
Changes in the Fair Value of Net Trading Derivatives and other investments
Beginning Balance		41,700,000		19,300,000
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	[1],[2]	(2,900,000)		2,100,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	0		0
Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income	[3]	0		0
Settlements		(32,400,000)		(15,600,000)
Transfers into Level 3	[4],[5]	0		0
Transfers out of Level 3	[5]	0		0
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	200,000		800,000
Assets and Liabilities Held for Sale related to KPCo		0
Ending Balance		6,600,000		6,600,000
Appalachian Power Co [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		10,000,000.0			17,600,000
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		10,000,000.0			17,600,000
Appalachian Power Co [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0			0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		4,300,000			5,800,000
Appalachian Power Co [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0			0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		7,000,000.0			42,000,000.0
Risk Management Assets
Risk Management Assets		7,000,000.0			42,000,000.0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		400,000			300,000
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	(4,300,000)			(5,800,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	(3,500,000)			(6,700,000)
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	7,000,000.0			42,000,000.0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	200,000			800,000
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	0			0
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	4,300,000			5,800,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	3,300,000			7,200,000
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	7,000,000.0			42,000,000.0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	400,000			300,000
Appalachian Power Co [Member] | Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		200,000			300,000
Appalachian Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	44.99			32.20
Appalachian Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	66.21			56.54
Appalachian Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13],[14]	55.42			44.77
Appalachian Power Co [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		7,000,000.0			42,000,000.0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		200,000			0
Appalachian Power Co [Member] | FTRs [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	0.15			(0.30)
Appalachian Power Co [Member] | FTRs [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	11.19			26.38
Appalachian Power Co [Member] | FTRs [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13],[14]	1.05			2.63
Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		7,600,000			7,000,000.0
Total Assets		4,200,000			(1,100,000)
Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		3,678,400,000			3,867,000,000
Total Assets		3,679,900,000			3,870,300,000
Changes in the Fair Value of Net Trading Derivatives and other investments
Beginning Balance		(700,000)		2,100,000
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	[1],[2]	3,800,000		300,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	0		0
Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income	[3]	0		0
Settlements		(2,300,000)		(1,400,000)
Transfers into Level 3	[4],[5]	0		0
Transfers out of Level 3	[5]	0		0
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	200,000		(300,000)
Assets and Liabilities Held for Sale related to KPCo		0
Ending Balance		1,000,000.0		700,000
Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		2,424,600,000			2,619,600,000
Total Assets		2,424,600,000			2,619,600,000
Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,246,200,000			1,240,400,000
Total Assets		1,249,000,000			1,244,200,000
Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Total Assets		2,100,000			7,600,000
Risk Management Assets
Risk Management Assets		2,100,000			7,600,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		1,100,000			8,300,000
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	(3,400,000)			(8,100,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	(2,800,000)			(10,000,000.0)
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	1,500,000			3,300,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	400,000			5,000,000.0
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	0			0
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	2,800,000			3,800,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	2,100,000			6,700,000
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	2,100,000			7,600,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	1,100,000			8,300,000
Indiana Michigan Power Co [Member] | Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		100,000			200,000
Indiana Michigan Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	44.99			32.20
Indiana Michigan Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	66.21			56.54
Indiana Michigan Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13],[14]	55.42			44.77
Indiana Michigan Power Co [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		2,100,000			7,600,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		1,000,000.0			8,100,000
Indiana Michigan Power Co [Member] | FTRs [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	(1.32)			(5.45)
Indiana Michigan Power Co [Member] | FTRs [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	11.50			17.78
Indiana Michigan Power Co [Member] | FTRs [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13],[14]	0.41			(0.12)
Ohio Power Co [Member]
Changes in the Fair Value of Net Trading Derivatives and other investments
Beginning Balance		(92,500,000)		(110,300,000)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	[1],[2]	500,000		0
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	0		0
Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income	[3]	0		0
Settlements		1,400,000		2,700,000
Transfers into Level 3	[4],[5]	0		0
Transfers out of Level 3	[5]	0		0
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	22,100,000		3,600,000
Assets and Liabilities Held for Sale related to KPCo		0
Ending Balance		(68,500,000)		(104,000,000.0)
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	(1,000,000.0)			(500,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[17]	0			0
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	100,000			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[17]	68,500,000			92,500,000
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[17]	0			0
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	1,100,000			500,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[17]	0			0
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[17]	68,500,000			92,500,000
Ohio Power Co [Member] | Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		68,500,000			92,500,000
Ohio Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	15.77			14.26
Ohio Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	83.20			52.98
Ohio Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13],[14]	38.10			30.68
Public Service Co Of Oklahoma [Member]
Changes in the Fair Value of Net Trading Derivatives and other investments
Beginning Balance		12,100,000		10,300,000
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	[1],[2]	12,100,000		9,300,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	0		0
Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income	[3]	0		0
Settlements		(19,800,000)		(16,300,000)
Transfers into Level 3	[4],[5]	0		0
Transfers out of Level 3	[5]	0		0
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	2,100,000		2,200,000
Assets and Liabilities Held for Sale related to KPCo		0
Ending Balance		6,500,000		5,500,000
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	(1,200,000)			(400,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	(700,000)			(100,000)
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	6,700,000			12,100,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	100,000			3,700,000
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	0			0
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	600,000			300,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	0			3,700,000
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	7,300,000			12,200,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	800,000			100,000
Public Service Co Of Oklahoma [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		7,300,000			12,200,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		800,000			100,000
Public Service Co Of Oklahoma [Member] | FTRs [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	(41.14)			(18.39)
Public Service Co Of Oklahoma [Member] | FTRs [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	11.59			1.87
Public Service Co Of Oklahoma [Member] | FTRs [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13],[14]	(3.69)			(2.57)
Southwestern Electric Power Co [Member]
Changes in the Fair Value of Net Trading Derivatives and other investments
Beginning Balance		10,900,000		1,600,000
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	[1],[2]	9,800,000		6,100,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	0		0
Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income	[3]	0		0
Settlements		(16,200,000)		(8,200,000)
Transfers into Level 3	[4],[5]	0		0
Transfers out of Level 3	[5]	0		0
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	11,200,000		1,000,000.0
Assets and Liabilities Held for Sale related to KPCo		0
Ending Balance		15,700,000		$ 500,000
Southwestern Electric Power Co [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		15,900,000			11,000,000.0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		200,000			100,000
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	(900,000)			(400,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	(200,000)			(100,000)
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	15,800,000			10,900,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	0			2,100,000
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	0			0
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	800,000			300,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	0			2,100,000
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[9],[17]	15,900,000			11,000,000.0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[9],[17]	200,000			100,000
Southwestern Electric Power Co [Member] | Natural Gas Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		10,100,000			3,600,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0			0
Southwestern Electric Power Co [Member] | Natural Gas Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[15]	5.23			3.11
Southwestern Electric Power Co [Member] | Natural Gas Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[15]	6.01			4.02
Southwestern Electric Power Co [Member] | Natural Gas Contracts [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[14],[15]	5.51			3.47
Southwestern Electric Power Co [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		5,800,000			7,400,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		200,000			100,000
Southwestern Electric Power Co [Member] | FTRs [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	(41.14)			(18.39)
Southwestern Electric Power Co [Member] | FTRs [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13]	11.59			1.87
Southwestern Electric Power Co [Member] | FTRs [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[13],[14]	(3.69)			(2.57)
Cash [Member] | Other [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents	[18]	0			0
Cash [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents	[18]	49,900,000			48,000,000.0
Other Short-term Investments	[19]	49,900,000			48,000,000.0
Cash [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents	[18]	49,900,000			48,000,000.0
Cash [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents	[18]	0			0
Cash [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents	[18]	0			0
Other Cash Deposits [Member] | Other [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		9,500,000			10,000,000.0
Other Cash Deposits [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		9,500,000			10,000,000.0
Other Cash Deposits [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		0			0
Other Cash Deposits [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		0			0
Other Cash Deposits [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		0			0
Mutual Funds Fixed Income [Member] | Other [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		0			0
Mutual Funds Fixed Income [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[20]	147,000,000.0			154,800,000
Mutual Funds Fixed Income [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		147,000,000.0			154,800,000
Mutual Funds Fixed Income [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		0			0
Mutual Funds Fixed Income [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		0			0
Mutual Funds Equity [Member] | Other [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[21]	0			0
Mutual Funds Equity [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[21]	52,000,000.0			55,600,000
Mutual Funds Equity [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[21]	52,000,000.0			55,600,000
Mutual Funds Equity [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[21]	0			0
Mutual Funds Equity [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[21]	0			0
Cash and Cash Equivalents [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[22]	7,600,000			7,000,000.0
Cash and Cash Equivalents [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[22]	21,800,000			84,700,000
Cash and Cash Equivalents [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[22]	14,200,000			77,700,000
Cash and Cash Equivalents [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[22]	0			0
Cash and Cash Equivalents [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[22]	0			0
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[22]	7,600,000			7,000,000.0
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[22]	21,800,000			84,700,000
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[22]	14,200,000			77,700,000
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[22]	0			0
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[22]	0			0
US Government Agencies Debt Securities [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
US Government Agencies Debt Securities [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,169,600,000			1,156,400,000
US Government Agencies Debt Securities [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
US Government Agencies Debt Securities [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,169,600,000			1,156,400,000
US Government Agencies Debt Securities [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,169,600,000			1,156,400,000
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,169,600,000			1,156,400,000
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Corporate Debt [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Corporate Debt [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		69,400,000			76,700,000
Corporate Debt [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Corporate Debt [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		69,400,000			76,700,000
Corporate Debt [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Corporate Debt [Member] | Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Corporate Debt [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		69,400,000			76,700,000
Corporate Debt [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Corporate Debt [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		69,400,000			76,700,000
Corporate Debt [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
State and Local Jurisdiction [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
State and Local Jurisdiction [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		7,200,000			7,300,000
State and Local Jurisdiction [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
State and Local Jurisdiction [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		7,200,000			7,300,000
State and Local Jurisdiction [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		7,200,000			7,300,000
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		7,200,000			7,300,000
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Fixed Income Funds [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Fixed Income Funds [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,246,200,000			1,240,400,000
Fixed Income Funds [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Fixed Income Funds [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,246,200,000			1,240,400,000
Fixed Income Funds [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,246,200,000			1,240,400,000
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,246,200,000			1,240,400,000
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Domestic [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[21]	0			0
Domestic [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[21]	2,410,400,000			2,541,900,000
Domestic [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[21]	2,410,400,000			2,541,900,000
Domestic [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[21]	0			0
Domestic [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[21]	0			0
Domestic [Member] | Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[21]	0			0
Domestic [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[21]	2,410,400,000			2,541,900,000
Domestic [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[21]	2,410,400,000			2,541,900,000
Domestic [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[21]	0			0
Domestic [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[21]	$ 0			$ 0

[1] Included in revenues on the statements of income.

[2] Represents the change in fair value between the beginning of the reporting period and the settlement of the risk management commodity contract.

[3] Included in cash flow hedges on the statements of comprehensive income.

[4] Represents existing assets or liabilities that were previously categorized as Level 2.

[5] Transfers are recognized based on their value at the beginning of the reporting period that the transfer occurred.

[6] Relates to the net gains (losses) of those contracts that are not reflected on the statements of income.  These changes in fair value are recorded as regulatory liabilities for net gains and as regulatory assets for net losses or accounts payable.

[7] Amount excludes Risk Management Assets classified as Assets Held for Sale on the balance sheets. See “Disposition of KPCo and KTCo” section of Note 6 for additional information.

[8] Amount excludes Risk Management Assets of $1.4 million and $6 million as of March 31, 2022 and December 31, 2021, respectively, classified as Assets Held for Sale on the balance sheets. See “Disposition of KPCo and KTCo” section of Note 6 for additional information.

[9] Amounts in “Other’’ column primarily represent counterparty netting of risk management and hedging contracts and associated cash collateral under the accounting guidance for “Derivatives and Hedging.’’

[10] The March 31, 2022 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were as follows: Level 1 matures $14 million in 2022 and $4 million in periods 2023-2025; Level 2 matures $96 million in 2022, $188 million in periods 2023-2025, $10 million in periods 2026-2027 and $4 million in periods 2028-2033; Level 3 matures $37 million in 2022, $8 million in periods 2023-2025, $13 million in periods 2026-2027 and $(11) million in periods 2028-2033.  Risk management commodity contracts are substantially comprised of power contracts.

[11] The December 31, 2021 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were as follows: Level 1 matures $1 million in 2022 and $1 million in periods 2023-2025; Level 2 matures $42 million in 2022, $109 million in periods 2023-2025, $10 million in periods 2026-2027 and $3 million in periods 2028-2033; Level 3 matures $82 million in 2022, $10 million in periods 2023-2025, $9 million in periods 2026-2027 and $(17) million in periods 2028-2033.  Risk management commodity contracts are substantially comprised of power contracts.

[12] Amount excludes Risk Management Liabilities of $0 and $0.1 million as of March 31, 2022 and December 31, 2021, respectively, classified as Liabilities Held for Sale on the balance sheets. See “Disposition of KPCo and KTCo” section of Note 6 for additional information.

[13] Represents market prices in dollars per MWh.

[14] The weighted average is the product of the forward market price of the underlying commodity and volume weighted by term.

[15] Represents market prices in dollars per MMBtu.

[16] See “Warrants Held in Investee” section of Note 9 for additional information.

[17] Substantially comprised of power contracts for the Registrant Subsidiaries.

[18] Amounts in “Other’’ column primarily represent cash deposits in bank accounts with financial institutions or third-parties.  Level 1 and Level 2 amounts primarily represent investments in money market funds.

[19] Primarily represents amounts held for the repayment of debt.

[20] Primarily short and intermediate maturities which may be sold and do not contain maturity dates.

[21] Amounts represent publicly traded equity securities and equity-based mutual funds.

[22] Amounts in “Other’’ column primarily represent accrued interest receivables from financial institutions.  Level 1 amounts primarily represent investments in money market funds.