Rate Matters East Companies (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2021	Dec. 31, 2020
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	$ 65,664.5	$ 63,901.6
AEP Transmission Co [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	11,376.5	10,772.8
Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	11,526.5	11,394.1
Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	7,073.4	7,052.3
Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	$ 7,676.2	$ 7,452.1
Kentucky Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Ownership Interest in Mitchell Power Plant	50.00%
Wheeling Power Company
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]
Requested Annual Increase	$ 40.0
Approved Return on Common Equity	9.20%
Total Basis Point Band for Authorized Return on Equity	140.00%
2020 Ohio Base Rate Case [Member] \| Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase	$ 42.0
Requested Return on Equity	10.15%
Staff Recommended Annual Revenue Cap for the DIR in 2022	$ 78.0
Staff Recommended Annual Revenue Cap for the DIR for the First Five Months of 2024	46.0
Proposed Settlement Annual Rate Increase	$ 68.0
Proposed Settlement Agreement ROE	9.70%
Settlement Annual Revenue Cap for the DIR in 2021	$ 57.0
Settlement Annual Revenue Cap for the DIR in 2022	91.0
Settlement Annual Revenue Cap for the DIR in 2023	116.0
Settlement Annual Revenue Cap for the DIR in for the first five months of 2024	51.0
Staff Recommended Annual Revenue Cap for the DIR in 2023	96.0
Staff Recommended Annual Revenue Cap for the DIR in 2021	57.0
2020 Ohio Base Rate Case [Member] \| Ohio Power Co [Member] \| Demand Side Management Programs
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	40.0
2020 Ohio Base Rate Case [Member] \| Ohio Power Co [Member] \| Employee Related Expense
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	23.0
2020 Ohio Base Rate Case [Member] \| Ohio Power Co [Member] \| Rate Base
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	19.0
2020 Ohio Base Rate Case [Member] \| Ohio Power Co [Member] \| Property Tax
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	17.0
2020 Ohio Base Rate Case [Member] \| Ohio Power Co [Member] \| Other Various Expenses
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	15.0
2020 Ohio Base Rate Case [Member] \| Ohio Power Co [Member] \| Vegetation Management Programs
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	10.0
2020 Ohio Base Rate Case [Member] \| Ohio Power Co [Member] \| Depreciation Expense
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	11.0
2019 DIR Audit [Member]
Public Utilities, General Disclosures [Line Items]
DIR Revenue Amount above 2019 Authorized Limit	17.0
CCR/ELG Filings \| Mitchell Power Plant
Public Utilities, General Disclosures [Line Items]
Investment in CCR/ELG	132.0
CCR Investment	2.0
ELG Investment	4.0
Property, Plant and Equipment, Net	1,200.0
Alternative CCR/ELG Investment	25.0
CCR/ELG Filings \| Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Investment in CCR/ELG	240.0
CCR Investment	8.0
ELG Investment	28.0
2021 Indiana Base Rate Case \| Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase	$ 104.0
Requested Return on Equity	10.00%
Phased In Annual Increase 2022	$ 73.0
Phased in Annual Increase 2023	31.0
Amount of Increase Related to Annual Depreciation Expense	$ 7.0
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%
Minimum [Member] \| 2020 Ohio Base Rate Case [Member] \| Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Staff Recommended Return on Common Equity	8.76%
Staff Recommended Annual Rate Decrease	$ 102.0
Minimum [Member] \| 2020 Ohio Base Rate Case [Member] \| Ohio Power Co [Member] \| Return on Common Equity
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	$ 9.0
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%
Maximum [Member] \| 2020 Ohio Base Rate Case [Member] \| Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Staff Recommended Return on Common Equity	9.78%
Staff Recommended Annual Rate Decrease	$ 123.0
Maximum [Member] \| 2020 Ohio Base Rate Case [Member] \| Ohio Power Co [Member] \| Return on Common Equity
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	30.0
Maximum [Member] \| 2020 Ohio Base Rate Case [Member] \| Ohio Power Co [Member] \| Plant in Service
Public Utilities, General Disclosures [Line Items]
Recommended Disallowance from Staff or Intervenors	$ 27.0

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