RATE MATTERS - I&M Rate Matters (Details) - INDIANA MICHIGAN POWER COMPANY - USD ($) $ in Millions	1 Months Ended
	Jan. 31, 2025	Jul. 31, 2024	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Aug. 31, 2023	Nov. 30, 2024
Public Utilities, General Disclosures [Line Items]
Earning test, over-earning credit to customers							$ 18.0
Subsequent Event
Public Utilities, General Disclosures [Line Items]
Earning test, over-earning credit to customers, proposed	$ 21.0
2023 Michigan Power Supply Cost Recovery | Minimum
Public Utilities, General Disclosures [Line Items]
Public utilities, recommended disallowance purchased power			$ 3.0
2023 Michigan Power Supply Cost Recovery | Maximum
Public Utilities, General Disclosures [Line Items]
Public utilities, recommended disallowance purchased power			$ 15.0
2023 Indiana Base Rate Case
Public Utilities, General Disclosures [Line Items]
Requested annual increase						$ 116.0
Requested return on equity						10.50%
Requested debt capital structure						48.80%
Requested equity capital structure						51.20%
Amount of increased depreciation expense requested						$ 41.0
Requested deferred storm costs						$ 15.0
Settlement agreement annual increase step one				$ 28.0
Settlement agreement annual increase step two				$ 34.0
Settlement agreement return on common equity				9.85%
Settlement agreement equity capital structure				50.00%
Settlement agreement debt capital structure				50.00%
Settlement agreement adjusted equity capital structure				51.20%
Settlement agreement increase related to depreciation expense				$ 25.0
Settlement agreement increase related to storm expense				$ 11.0
2023 Indiana Base Rate Case | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Approved annual base rate increase	$ 15.0
2023 Michigan Base Rate Case
Public Utilities, General Disclosures [Line Items]
Requested annual increase					$ 34.0
Requested return on equity					10.50%
Requested debt capital structure					49.40%
Requested equity capital structure					50.60%
Amount of increased depreciation expense requested					$ 11.0
Approved annual base rate increase		$ 17.0
Approved return on equity		9.86%
Approved debt capital structure		52.00%
Approved equity capital structure		48.00%