Fair Value Long-term Debt, Other Temporary Investments, Nuclear Trusts (Details) - USD ($)		3 Months Ended		6 Months Ended			12 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022		Jun. 30, 2021	Dec. 31, 2021
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	[1]	$ 35,459,400,000		$ 35,459,400,000			$ 33,454,500,000
Long Term Debt, Fair Value	[2],[3]	33,197,500,000		33,197,500,000			37,564,700,000
Other Temporary Investments
Cost		223,000,000.0		223,000,000.0			232,000,000.0
Gross Unrealized Gains		21,100,000		21,100,000			36,400,000
Gross Unrealized Losses		(6,200,000)		(6,200,000)			0
Other Short-term Investments		237,900,000		237,900,000			268,400,000
Debt and Equity Securities Within Other Temporary Investments
Proceeds from Investment Sales		11,100,000	$ 3,600,000	15,000,000.0		$ 9,100,000
Purchases of Investments		800,000	12,400,000	1,600,000		13,100,000
Gross Realized Gains on Investment Sales		3,300,000	1,100,000	3,600,000		1,200,000
Gross Realized Losses on Investment Sales		400,000	0	500,000		0
Nuclear Trust Fund Investments
Fair Value		3,280,800,000		3,280,800,000			3,867,000,000
Contractual Maturities, Fair Value of Debt Securities
Fair Value		3,280,800,000		3,280,800,000			3,867,000,000
Fair Value Measurements (Textuals)
Liabilities Held for Sale		1,900,300,000		1,900,300,000			1,880,900,000
Spent Nuclear Fuel and Decommissioning Trusts [Member]
Unrealized Gain on Securities				1,400,000,000			1,900,000,000
Nuclear Trust Fund Investments
Gross Unrealized Gains				1,406,200,000			1,974,700,000
Securities Activity Within Decommissioning and SNF Trusts
Proceeds from Investment Sales		736,400,000	802,700,000	1,229,900,000		1,122,700,000
Purchases of Investments		745,500,000	812,800,000	1,253,200,000		1,149,700,000
Gross Realized Gains on Investment Sales		10,900,000	83,300,000	16,700,000		88,700,000
Gross Realized Losses on Investment Sales		17,900,000	1,300,000	25,100,000		5,500,000
Contractual Maturities, Fair Value of Debt Securities
Within 1 year		356,200,000		356,200,000
After 1 year through 5 years		398,500,000		398,500,000
After 5 years through 10 years		248,000,000.0		248,000,000.0
After 10 years		206,200,000		206,200,000
Fair Value Measurements (Textuals)
Adjusted Cost of Debt Securities		1,200,000,000		1,200,000,000			1,200,000,000
Adjusted Cost of Domestic Equity Securities		650,000,000		650,000,000			641,000,000
Unrealized Loss on Securities				11,000,000			4,000,000
Other than Temporary Impairment Losses, Investments				(20,800,000)			(10,100,000)
Cash [Member]
Other Temporary Investments
Cost	[4]	45,900,000		45,900,000			48,000,000.0
Gross Unrealized Gains	[4]	0		0			0
Gross Unrealized Losses	[4]	0		0			0
Other Short-term Investments	[4]	45,900,000		45,900,000			48,000,000.0
Fixed Income Funds [Member]
Nuclear Trust Fund Investments
Fair Value		1,208,900,000		1,208,900,000			1,240,400,000
Contractual Maturities, Fair Value of Debt Securities
Fair Value		1,208,900,000		1,208,900,000			1,240,400,000
Fixed Income Funds [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains				1,200,000			73,400,000
Fair Value Measurements (Textuals)
Other than Temporary Impairment Losses, Investments				(20,800,000)			(10,100,000)
Mutual Funds Fixed Income [Member]
Other Temporary Investments
Cost	[5]	146,600,000		146,600,000			154,300,000
Gross Unrealized Gains	[5]	0		0			500,000
Gross Unrealized Losses	[5]	(6,200,000)		(6,200,000)			0
Other Short-term Investments	[5]	140,400,000		140,400,000			154,800,000
Domestic [Member]
Nuclear Trust Fund Investments
Fair Value	[6]	2,055,300,000		2,055,300,000			2,541,900,000
Contractual Maturities, Fair Value of Debt Securities
Fair Value	[6]	2,055,300,000		2,055,300,000			2,541,900,000
Domestic [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains	[7]			1,405,000,000			1,901,300,000
Fair Value Measurements (Textuals)
Other than Temporary Impairment Losses, Investments				0			0
Mutual Funds Equity [Member]
Other Temporary Investments
Cost		17,100,000		17,100,000			19,700,000
Gross Unrealized Gains		21,100,000		21,100,000			35,900,000
Gross Unrealized Losses		0		0			0
Other Short-term Investments	[6]	38,200,000		38,200,000			55,600,000
Cash and Cash Equivalents [Member]
Nuclear Trust Fund Investments
Fair Value	[8]	16,600,000		16,600,000			84,700,000
Contractual Maturities, Fair Value of Debt Securities
Fair Value	[8]	16,600,000		16,600,000			84,700,000
Cash and Cash Equivalents [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains				0			0
Fair Value Measurements (Textuals)
Other than Temporary Impairment Losses, Investments				0			0
US Government Agencies Debt Securities [Member]
Nuclear Trust Fund Investments
Fair Value		1,139,500,000		1,139,500,000			1,156,400,000
Contractual Maturities, Fair Value of Debt Securities
Fair Value		1,139,500,000		1,139,500,000			1,156,400,000
US Government Agencies Debt Securities [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains				5,300,000			66,300,000
Fair Value Measurements (Textuals)
Other than Temporary Impairment Losses, Investments				(14,700,000)			(7,900,000)
Corporate Debt [Member]
Nuclear Trust Fund Investments
Fair Value		62,300,000		62,300,000			76,700,000
Contractual Maturities, Fair Value of Debt Securities
Fair Value		62,300,000		62,300,000			76,700,000
Corporate Debt [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains				(4,200,000)			6,700,000
Fair Value Measurements (Textuals)
Other than Temporary Impairment Losses, Investments				(6,000,000.0)			(2,100,000)
State and Local Jurisdiction [Member]
Nuclear Trust Fund Investments
Fair Value		7,100,000		7,100,000			7,300,000
Contractual Maturities, Fair Value of Debt Securities
Fair Value		7,100,000		7,100,000			7,300,000
State and Local Jurisdiction [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains				100,000			400,000
Fair Value Measurements (Textuals)
Other than Temporary Impairment Losses, Investments				(100,000)			(100,000)
Other Cash Deposits [Member]
Other Temporary Investments
Cost		13,400,000		13,400,000			10,000,000.0
Gross Unrealized Gains		0		0			0
Gross Unrealized Losses		0		0			0
Other Short-term Investments		13,400,000		13,400,000			10,000,000.0
AEP Texas Inc. [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		6,128,200,000		6,128,200,000			5,180,800,000
Long Term Debt, Fair Value		5,730,500,000		5,730,500,000			5,663,800,000
AEP Transmission Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		4,885,600,000		4,885,600,000			4,343,900,000
Long Term Debt, Fair Value		4,438,100,000		4,438,100,000			4,968,200,000
Fair Value Measurements (Textuals)
Liabilities Held for Sale		27,600,000		27,600,000			27,600,000
Appalachian Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		4,927,200,000		4,927,200,000			4,938,900,000
Long Term Debt, Fair Value		4,907,800,000		4,907,800,000			6,037,100,000
Indiana Michigan Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		3,228,700,000		3,228,700,000			3,195,000,000
Long Term Debt, Fair Value		3,072,200,000		3,072,200,000			3,748,000,000
Nuclear Trust Fund Investments
Fair Value		3,280,800,000		3,280,800,000			3,867,000,000
Contractual Maturities, Fair Value of Debt Securities
Fair Value		3,280,800,000		3,280,800,000			3,867,000,000
Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Unrealized Gain on Securities				1,400,000,000			1,900,000,000
Nuclear Trust Fund Investments
Gross Unrealized Gains				1,406,200,000			1,974,700,000
Securities Activity Within Decommissioning and SNF Trusts
Proceeds from Investment Sales		736,400,000	802,700,000	1,229,900,000		1,122,700,000
Purchases of Investments		745,500,000	812,800,000	1,253,200,000		1,149,700,000
Gross Realized Gains on Investment Sales		10,900,000	83,300,000	16,700,000		88,700,000
Gross Realized Losses on Investment Sales		17,900,000	$ 1,300,000	25,100,000		$ 5,500,000
Contractual Maturities, Fair Value of Debt Securities
Within 1 year		356,200,000		356,200,000
After 1 year through 5 years		398,500,000		398,500,000
After 5 years through 10 years		248,000,000.0		248,000,000.0
After 10 years		206,200,000		206,200,000
Fair Value Measurements (Textuals)
Adjusted Cost of Debt Securities		1,200,000,000		1,200,000,000			1,200,000,000
Adjusted Cost of Domestic Equity Securities		650,000,000		650,000,000			641,000,000
Unrealized Loss on Securities				11,000,000			4,000,000
Other than Temporary Impairment Losses, Investments				(20,800,000)			(10,100,000)
Indiana Michigan Power Co [Member] | Fixed Income Funds [Member]
Nuclear Trust Fund Investments
Fair Value		1,208,900,000		1,208,900,000			1,240,400,000
Contractual Maturities, Fair Value of Debt Securities
Fair Value		1,208,900,000		1,208,900,000			1,240,400,000
Indiana Michigan Power Co [Member] | Fixed Income Funds [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains				1,200,000			73,400,000
Fair Value Measurements (Textuals)
Other than Temporary Impairment Losses, Investments				(20,800,000)			(10,100,000)
Indiana Michigan Power Co [Member] | Domestic [Member]
Nuclear Trust Fund Investments
Fair Value	[6]	2,055,300,000		2,055,300,000			2,541,900,000
Contractual Maturities, Fair Value of Debt Securities
Fair Value	[6]	2,055,300,000		2,055,300,000			2,541,900,000
Indiana Michigan Power Co [Member] | Domestic [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains				1,405,000,000	[7]		1,901,300,000
Fair Value Measurements (Textuals)
Other than Temporary Impairment Losses, Investments				0			0
Indiana Michigan Power Co [Member] | Cash and Cash Equivalents [Member]
Nuclear Trust Fund Investments
Fair Value	[8]	16,600,000		16,600,000			84,700,000
Contractual Maturities, Fair Value of Debt Securities
Fair Value	[8]	16,600,000		16,600,000			84,700,000
Indiana Michigan Power Co [Member] | Cash and Cash Equivalents [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains				0			0
Fair Value Measurements (Textuals)
Other than Temporary Impairment Losses, Investments				0			0
Indiana Michigan Power Co [Member] | US Government Agencies Debt Securities [Member]
Nuclear Trust Fund Investments
Fair Value		1,139,500,000		1,139,500,000			1,156,400,000
Contractual Maturities, Fair Value of Debt Securities
Fair Value		1,139,500,000		1,139,500,000			1,156,400,000
Indiana Michigan Power Co [Member] | US Government Agencies Debt Securities [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains				5,300,000			66,300,000
Fair Value Measurements (Textuals)
Other than Temporary Impairment Losses, Investments				(14,700,000)			(7,900,000)
Indiana Michigan Power Co [Member] | Corporate Debt [Member]
Nuclear Trust Fund Investments
Fair Value		62,300,000		62,300,000			76,700,000
Contractual Maturities, Fair Value of Debt Securities
Fair Value		62,300,000		62,300,000			76,700,000
Indiana Michigan Power Co [Member] | Corporate Debt [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains				(4,200,000)			6,700,000
Fair Value Measurements (Textuals)
Other than Temporary Impairment Losses, Investments				(6,000,000.0)			(2,100,000)
Indiana Michigan Power Co [Member] | State and Local Jurisdiction [Member]
Nuclear Trust Fund Investments
Fair Value		7,100,000		7,100,000			7,300,000
Contractual Maturities, Fair Value of Debt Securities
Fair Value		7,100,000		7,100,000			7,300,000
Indiana Michigan Power Co [Member] | State and Local Jurisdiction [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains				100,000			400,000
Fair Value Measurements (Textuals)
Other than Temporary Impairment Losses, Investments				(100,000)			(100,000)
Ohio Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		2,969,400,000		2,969,400,000			2,968,500,000
Long Term Debt, Fair Value		2,679,000,000		2,679,000,000			3,437,500,000
Public Service Co Of Oklahoma [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		2,413,800,000		2,413,800,000			1,913,500,000
Long Term Debt, Fair Value		2,236,200,000		2,236,200,000			2,163,700,000
Southwestern Electric Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		3,393,400,000		3,393,400,000			3,395,200,000
Long Term Debt, Fair Value		3,045,600,000		3,045,600,000			3,792,900,000
Risk Management Commodity Contracts [Member]
Fair Value Measurements (Textuals)
Liabilities Held for Sale							100,000
Equity Units [Member]
Book Values and Fair Values of Long - term Debt
Long Term Debt, Fair Value		923,000,000		923,000,000			1,700,000,000
Held For Sale
Fair Value Measurements (Textuals)
Liabilities Held for Sale		1,100,000,000		1,100,000,000			1,100,000,000
Fair Value Held for Sale [Member]
Fair Value Measurements (Textuals)
Liabilities Held for Sale		$ 1,100,000,000		$ 1,100,000,000			$ 1,200,000,000

[1] The book value amounts exclude Long-term Debt of $1.1 billion and $1.1 billion as of June 30, 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.

[2] The fair value amounts exclude Long-term Debt of $1.1 billion and $1.2 billion as of June 30, 2022 and December 31, 2021, respectively, related to KPCo. See “Disposition of KPCo and KTCo” section of Note 6 for additional information.

[3] The fair value amounts include debt related to AEP’s Equity Units and had a fair value of $923 million and $1.7 billion as of June 30, 2022 and December 31, 2021, respectively. See “Equity Units” section of Note 12 for additional information.

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

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

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

[7] Amount reported as Gross Unrealized Gains includes unrealized gains of $1.4 billion and $1.9 billion and unrealized losses of $11 million and $4 million as of June 30, 2022 and December 31, 2021, respectively.

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