EFFECTS OF REGULATION - Regulatory Liabilities - AEP Texas (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Regulatory Liability [Line Items]
Total Current Regulatory Liabilities	$ 53.5	$ 26.5
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	8,344.0	8,182.4
Pending final regulatory determination
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	322.0	207.9
Approved for payment
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	8,022.0	7,974.5
Pays/paying a return | Pending final regulatory determination
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	176.0	103.1
Pays/paying a return | Pending final regulatory determination | Income Taxes, Net
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	176.0	103.1
Pays/paying a return | Approved for payment
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	5,526.4	5,823.1
Pays/paying a return | Approved for payment | Income Taxes, Net
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	1,622.1	2,179.7
Regulatory liabilities, not subject to rate normalization requirements, amount	$ 192.0	228.0
Regulatory liabilities, not subject to rate normalization requirements, refund period	10 years
Pays/paying a return | Approved for payment | Asset Removal Costs
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	$ 3,828.0	3,563.5
Pays/paying a return | Approved for payment | Other Regulatory Liabilities Approved for Payment
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	40.4	35.0
Does not pay/paying a return | Pending final regulatory determination
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	146.0	104.8
Does not pay/paying a return | Pending final regulatory determination | Other Regulatory Liabilities Pending Final Regulatory Determination
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	14.7	1.7
Does not pay/paying a return | Approved for payment
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	2,495.6	2,151.4
Does not pay/paying a return | Approved for payment | Other Regulatory Liabilities Approved for Payment
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	90.1	106.5
AEP TEXAS INC.
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	1,285.4	1,261.4
AEP TEXAS INC. | Pending final regulatory determination
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	0.0	14.5
AEP TEXAS INC. | Approved for payment
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	1,285.4	1,246.9
AEP TEXAS INC. | Pays/paying a return | Pending final regulatory determination
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	0.0	13.0
AEP TEXAS INC. | Pays/paying a return | Pending final regulatory determination | Income Taxes, Net
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	0.0	13.0
AEP TEXAS INC. | Pays/paying a return | Approved for payment
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	1,258.2	1,212.9
AEP TEXAS INC. | Pays/paying a return | Approved for payment | Income Taxes, Net
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	409.4	412.0
Regulatory liabilities, not subject to rate normalization requirements, amount	$ 22.0
Regulatory liabilities, not subject to rate normalization requirements, refund period	5 years
AEP TEXAS INC. | Pays/paying a return | Approved for payment | Asset Removal Costs
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	$ 844.0	797.1
AEP TEXAS INC. | Pays/paying a return | Approved for payment | Other Regulatory Liabilities Approved for Payment
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	4.8	3.8
AEP TEXAS INC. | Does not pay/paying a return | Pending final regulatory determination
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	0.0	1.5
AEP TEXAS INC. | Does not pay/paying a return | Pending final regulatory determination | Other Regulatory Liabilities Pending Final Regulatory Determination
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	0.0	1.5
AEP TEXAS INC. | Does not pay/paying a return | Approved for payment
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	27.2	34.0
AEP TEXAS INC. | Does not pay/paying a return | Approved for payment | Other Regulatory Liabilities Approved for Payment
Regulatory Liability [Line Items]
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	$ 5.6	7.4
AEP TEXAS INC. | Does not pay/paying a return | Approved for payment | Transition and Restoration Charges
Regulatory Liability [Line Items]
Remaining Refund Period	5 years
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	$ 21.6	$ 26.6