BENEFIT PLANS - Schedule of Amounts Included in Regulatory Assets, Deferred Income Taxes and AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain) Loss	$ 1,153.5	$ 1,063.4
Prior Service Cost	0.2	0.2
Actuarial Gain (Loss) During the Year	188.0	129.2
Amortization of Actuarial Loss	(4.5)	(1.4)
Amounts Recognized Due to Settlement	(93.4)
Change for the Year	90.1	127.8
Pension Plans | Regulatory Assets
Defined Benefit Plan Disclosure [Line Items]
Recorded as	1,019.8	938.6
Pension Plans | Deferred Income Taxes
Defined Benefit Plan Disclosure [Line Items]
Recorded as	28.2	26.4
Pension Plans | Net of Tax AOCI
Defined Benefit Plan Disclosure [Line Items]
Recorded as	105.7	98.6
Pension Plans | AEP TEXAS INC.
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain) Loss	189.3	175.2
Prior Service Cost	0.0	0.0
Actuarial Gain (Loss) During the Year	24.2	13.4
Amortization of Actuarial Loss	(0.3)	(0.1)
Amounts Recognized Due to Settlement	(9.8)
Change for the Year	14.1	13.3
Pension Plans | AEP TEXAS INC. | Regulatory Assets
Defined Benefit Plan Disclosure [Line Items]
Recorded as	176.7	163.4
Pension Plans | AEP TEXAS INC. | Deferred Income Taxes
Defined Benefit Plan Disclosure [Line Items]
Recorded as	2.8	2.7
Pension Plans | AEP TEXAS INC. | Net of Tax AOCI
Defined Benefit Plan Disclosure [Line Items]
Recorded as	9.8	9.1
Pension Plans | APPALACHIAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain) Loss	112.1	104.9
Prior Service Cost	0.0	0.0
Actuarial Gain (Loss) During the Year	19.4	9.3
Amortization of Actuarial Loss	(0.4)	0.0
Amounts Recognized Due to Settlement	(11.8)
Change for the Year	7.2	9.3
Pension Plans | APPALACHIAN POWER COMPANY | Regulatory Assets
Defined Benefit Plan Disclosure [Line Items]
Recorded as	109.9	102.6
Pension Plans | APPALACHIAN POWER COMPANY | Deferred Income Taxes
Defined Benefit Plan Disclosure [Line Items]
Recorded as	0.4	0.4
Pension Plans | APPALACHIAN POWER COMPANY | Net of Tax AOCI
Defined Benefit Plan Disclosure [Line Items]
Recorded as	1.8	1.9
Pension Plans | INDIANA MICHIGAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain) Loss	7.5	(5.8)
Prior Service Cost	0.0	0.0
Actuarial Gain (Loss) During the Year	23.0	1.2
Amortization of Actuarial Loss	(0.4)	(0.1)
Amounts Recognized Due to Settlement	(9.3)
Change for the Year	13.3	1.1
Pension Plans | INDIANA MICHIGAN POWER COMPANY | Regulatory Assets
Defined Benefit Plan Disclosure [Line Items]
Recorded as	17.5	6.4
Pension Plans | INDIANA MICHIGAN POWER COMPANY | Deferred Income Taxes
Defined Benefit Plan Disclosure [Line Items]
Recorded as	(2.2)	(2.6)
Pension Plans | INDIANA MICHIGAN POWER COMPANY | Net of Tax AOCI
Defined Benefit Plan Disclosure [Line Items]
Recorded as	(7.8)	(9.6)
Pension Plans | OHIO POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain) Loss	140.9	131.9
Prior Service Cost	0.0	0.0
Actuarial Gain (Loss) During the Year	15.8	7.6
Amortization of Actuarial Loss	(0.3)	0.0
Amounts Recognized Due to Settlement	(6.5)
Change for the Year	9.0	7.6
Pension Plans | OHIO POWER COMPANY | Regulatory Assets
Defined Benefit Plan Disclosure [Line Items]
Recorded as	140.9	131.9
Pension Plans | OHIO POWER COMPANY | Deferred Income Taxes
Defined Benefit Plan Disclosure [Line Items]
Recorded as	0.0	0.0
Pension Plans | OHIO POWER COMPANY | Net of Tax AOCI
Defined Benefit Plan Disclosure [Line Items]
Recorded as	0.0	0.0
Pension Plans | PUBLIC SERVICE COMPANY OF OKLAHOMA
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain) Loss	53.8	46.7
Prior Service Cost	0.0	0.0
Actuarial Gain (Loss) During the Year	12.5	7.9
Amortization of Actuarial Loss	(0.2)	0.0
Amounts Recognized Due to Settlement	(5.2)
Change for the Year	7.1	7.9
Pension Plans | PUBLIC SERVICE COMPANY OF OKLAHOMA | Regulatory Assets
Defined Benefit Plan Disclosure [Line Items]
Recorded as	53.8	46.7
Pension Plans | PUBLIC SERVICE COMPANY OF OKLAHOMA | Deferred Income Taxes
Defined Benefit Plan Disclosure [Line Items]
Recorded as	0.0	0.0
Pension Plans | PUBLIC SERVICE COMPANY OF OKLAHOMA | Net of Tax AOCI
Defined Benefit Plan Disclosure [Line Items]
Recorded as	0.0	0.0
Pension Plans | SOUTHWESTERN ELECTRIC POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain) Loss	82.9	89.6
Prior Service Cost	0.0	0.0
Actuarial Gain (Loss) During the Year	2.7	12.1
Amortization of Actuarial Loss	(0.1)	(0.1)
Amounts Recognized Due to Settlement	(9.3)
Change for the Year	(6.7)	12.0
Pension Plans | SOUTHWESTERN ELECTRIC POWER COMPANY | Regulatory Assets
Defined Benefit Plan Disclosure [Line Items]
Recorded as	83.0	89.7
Pension Plans | SOUTHWESTERN ELECTRIC POWER COMPANY | Deferred Income Taxes
Defined Benefit Plan Disclosure [Line Items]
Recorded as	0.0	0.0
Pension Plans | SOUTHWESTERN ELECTRIC POWER COMPANY | Net of Tax AOCI
Defined Benefit Plan Disclosure [Line Items]
Recorded as	(0.1)	(0.1)
OPEB
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain) Loss	(41.6)	201.5
Prior Service Cost	(14.7)	(27.4)
Actuarial Gain (Loss) During the Year	(240.1)	(83.7)
Amortization of Actuarial Loss	(3.0)	(14.8)
Amortization of Prior Service Credit	12.7	63.1
Change for the Year	(230.4)	(35.4)
OPEB | Regulatory Assets
Defined Benefit Plan Disclosure [Line Items]
Recorded as	(55.4)	106.1
OPEB | Deferred Income Taxes
Defined Benefit Plan Disclosure [Line Items]
Recorded as	(0.1)	14.3
OPEB | Net of Tax AOCI
Defined Benefit Plan Disclosure [Line Items]
Recorded as	(0.8)	53.7
OPEB | AEP TEXAS INC.
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain) Loss	1.6	22.1
Prior Service Cost	(1.3)	(2.3)
Actuarial Gain (Loss) During the Year	(20.3)	(6.4)
Amortization of Actuarial Loss	(0.2)	(1.2)
Amortization of Prior Service Credit	1.0	5.3
Change for the Year	(19.5)	(2.3)
OPEB | AEP TEXAS INC. | Regulatory Assets
Defined Benefit Plan Disclosure [Line Items]
Recorded as	0.8	19.8
OPEB | AEP TEXAS INC. | Deferred Income Taxes
Defined Benefit Plan Disclosure [Line Items]
Recorded as	0.0	0.0
OPEB | AEP TEXAS INC. | Net of Tax AOCI
Defined Benefit Plan Disclosure [Line Items]
Recorded as	(0.5)	0.0
OPEB | APPALACHIAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain) Loss	(9.9)	27.1
Prior Service Cost	(2.3)	(4.2)
Actuarial Gain (Loss) During the Year	(36.6)	(11.1)
Amortization of Actuarial Loss	(0.4)	(2.3)
Amortization of Prior Service Credit	1.9	9.2
Change for the Year	(35.1)	(4.2)
OPEB | APPALACHIAN POWER COMPANY | Regulatory Assets
Defined Benefit Plan Disclosure [Line Items]
Recorded as	(2.0)	13.2
OPEB | APPALACHIAN POWER COMPANY | Deferred Income Taxes
Defined Benefit Plan Disclosure [Line Items]
Recorded as	(2.2)	2.0
OPEB | APPALACHIAN POWER COMPANY | Net of Tax AOCI
Defined Benefit Plan Disclosure [Line Items]
Recorded as	(8.0)	7.7
OPEB | INDIANA MICHIGAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain) Loss	2.3	28.7
Prior Service Cost	(2.0)	(3.7)
Actuarial Gain (Loss) During the Year	(25.9)	(9.6)
Amortization of Actuarial Loss	(0.5)	(1.9)
Amortization of Prior Service Credit	1.7	8.7
Change for the Year	(24.7)	(2.8)
OPEB | INDIANA MICHIGAN POWER COMPANY | Regulatory Assets
Defined Benefit Plan Disclosure [Line Items]
Recorded as	(2.9)	19.0
OPEB | INDIANA MICHIGAN POWER COMPANY | Deferred Income Taxes
Defined Benefit Plan Disclosure [Line Items]
Recorded as	0.7	1.3
OPEB | INDIANA MICHIGAN POWER COMPANY | Net of Tax AOCI
Defined Benefit Plan Disclosure [Line Items]
Recorded as	2.5	4.7
OPEB | OHIO POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain) Loss	(5.3)	18.1
Prior Service Cost	(1.6)	(2.9)
Actuarial Gain (Loss) During the Year	(23.0)	(7.9)
Amortization of Actuarial Loss	(0.4)	(1.6)
Amortization of Prior Service Credit	1.3	6.3
Change for the Year	(22.1)	(3.2)
OPEB | OHIO POWER COMPANY | Regulatory Assets
Defined Benefit Plan Disclosure [Line Items]
Recorded as	(6.9)	15.2
OPEB | OHIO POWER COMPANY | Deferred Income Taxes
Defined Benefit Plan Disclosure [Line Items]
Recorded as	0.0	0.0
OPEB | OHIO POWER COMPANY | Net of Tax AOCI
Defined Benefit Plan Disclosure [Line Items]
Recorded as	0.0	0.0
OPEB | PUBLIC SERVICE COMPANY OF OKLAHOMA
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain) Loss	4.7	17.5
Prior Service Cost	(0.9)	(1.6)
Actuarial Gain (Loss) During the Year	(12.6)	(3.7)
Amortization of Actuarial Loss	(0.2)	(0.8)
Amortization of Prior Service Credit	0.7	4.0
Change for the Year	(12.1)	(0.5)
OPEB | PUBLIC SERVICE COMPANY OF OKLAHOMA | Regulatory Assets
Defined Benefit Plan Disclosure [Line Items]
Recorded as	3.8	15.9
OPEB | PUBLIC SERVICE COMPANY OF OKLAHOMA | Deferred Income Taxes
Defined Benefit Plan Disclosure [Line Items]
Recorded as	0.0	0.0
OPEB | PUBLIC SERVICE COMPANY OF OKLAHOMA | Net of Tax AOCI
Defined Benefit Plan Disclosure [Line Items]
Recorded as	0.0	0.0
OPEB | SOUTHWESTERN ELECTRIC POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain) Loss	0.0	18.4
Prior Service Cost	(1.0)	(2.1)
Actuarial Gain (Loss) During the Year	(18.1)	(5.6)
Amortization of Actuarial Loss	(0.3)	(1.0)
Amortization of Prior Service Credit	1.1	4.9
Change for the Year	(17.3)	(1.7)
OPEB | SOUTHWESTERN ELECTRIC POWER COMPANY | Regulatory Assets
Defined Benefit Plan Disclosure [Line Items]
Recorded as	0.5	10.2
OPEB | SOUTHWESTERN ELECTRIC POWER COMPANY | Deferred Income Taxes
Defined Benefit Plan Disclosure [Line Items]
Recorded as	(0.3)	1.3
OPEB | SOUTHWESTERN ELECTRIC POWER COMPANY | Net of Tax AOCI
Defined Benefit Plan Disclosure [Line Items]
Recorded as	$ (1.2)	$ 4.8