Rate Matters East Companies (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	$ 67,878.0	$ 66,001.3
AEP Transmission Co [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	12,163.8	11,935.7
Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	11,873.3	11,804.3
Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	7,312.2	7,310.9
Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	$ 8,067.5	$ 7,963.0
Kentucky Power Co [Member] | Mitchell Power Plant
Public Utilities, General Disclosures [Line Items]
Ownership Interest in Mitchell Power Plant	50.00%
Wheeling Power Company | Mitchell Power Plant
Public Utilities, General Disclosures [Line Items]
Ownership Interest in Mitchell Power Plant	50.00%
2017-2019 Virginia Triennial Review [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Approved Return on Common Equity	9.20%
Total Basis Point Band for Authorized Return on Equity	14000.00%
CCR/ELG Filings | Mitchell Power Plant
Public Utilities, General Disclosures [Line Items]
Investment in CCR/ELG	$ 132.0
Estimated alternative CCR Investment	25.0
CCR/ELG Filings | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
ELG Investment	41.0
Net Book Value of Amos and Mountaineer Plants - Virginia	1,500.0
Estimated ELG Costs	197.0
CCR/ELG Filings | Kentucky Power Co [Member] | Mitchell Power Plant
Public Utilities, General Disclosures [Line Items]
ELG Investment	4.0
Property, Plant and Equipment, Net	585.0
2021 and 2021 ENEC Filing | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
2021 Requested Increase in ENEC Revenues	73.0
2021 Cumulative ENEC Under Recovery	55.0
2021 Projected ENEC Cost Incease	18.0
2021 Approved ENEC Rate Increase	7.0
2021 Approved Reduction in ENEC Projected Costs	48.0
2021 Modified Reduction in ENEC Projected Costs	17.0
2022 Requested Increase in ENEC Rates	155.0
Current Cumulative ENEC Under Recovery	243.0
2022 Requested Increase in ENEC Rates Second Filing	297.0
Michigan Power Supply Cost Recovery Reconciliation | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
ALJ Recommended Disallowance	$ 8.0
Minimum [Member] | 2017-2019 Virginia Triennial Review [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Approved Return on Common Equity	8.50%
Maximum [Member] | 2017-2019 Virginia Triennial Review [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Approved Return on Common Equity	9.90%