EFFECTS OF REGULATION - Regulatory Assets - AEP Texas (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	$ 4,804	$ 5,129
Pending final regulatory approval
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	1,307	1,311
Approved for recovery
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	3,497	3,818
Earns/earning a return | Pending final regulatory approval
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	435	395
Earns/earning a return | Pending final regulatory approval | Unified Tracker Mechanism Deferred Costs
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	56	0
Earns/earning a return | Pending final regulatory approval | Storm-Related Costs
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	43	51
Earns/earning a return | Pending final regulatory approval | Other Regulatory Assets Pending Final Regulatory Approval
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	23	21
Earns/earning a return | Approved for recovery
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	1,341	1,711
Earns/earning a return | Approved for recovery | Storm-Related Costs
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	$ 100	107
Remaining Recovery Period	6 years
Earns/earning a return | Approved for recovery | Texas Mobile Temporary Emergency Electric Energy Facilities Rider
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	$ 27	33
Remaining Recovery Period	2 years
Earns/earning a return | Approved for recovery | Other Regulatory Assets Approved for Recovery
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	$ 199	204
Does not earns/earning a return | Pending final regulatory approval
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	872	916
Does not earns/earning a return | Pending final regulatory approval | Storm-Related Costs
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	191	301
Does not earns/earning a return | Pending final regulatory approval | Other Regulatory Assets Pending Final Regulatory Approval
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	163	87
Does not earns/earning a return | Approved for recovery
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	2,156	2,107
Does not earns/earning a return | Approved for recovery | Storm-Related Costs
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	$ 158	67
Remaining Recovery Period	6 years
Does not earns/earning a return | Approved for recovery | Other Regulatory Assets Approved for Recovery
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	$ 222	229
Does not earns/earning a return | Approved for recovery | Pension and OPEB Funded Status
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	$ 796	974
Remaining Recovery Period	12 years
AEP TEXAS INC.
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	$ 402	354
AEP TEXAS INC. | Pending final regulatory approval
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	181	77
AEP TEXAS INC. | Approved for recovery
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	221	277
AEP TEXAS INC. | Earns/earning a return | Pending final regulatory approval
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	114	41
AEP TEXAS INC. | Earns/earning a return | Pending final regulatory approval | Unified Tracker Mechanism Deferred Costs
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	56	0
AEP TEXAS INC. | Earns/earning a return | Pending final regulatory approval | Storm-Related Costs
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	41	41
AEP TEXAS INC. | Earns/earning a return | Pending final regulatory approval | System Resiliency Plan Deferred Costs
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	17	0
AEP TEXAS INC. | Earns/earning a return | Approved for recovery
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	49	61
AEP TEXAS INC. | Earns/earning a return | Approved for recovery | Texas Mobile Temporary Emergency Electric Energy Facilities Rider
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	$ 27	33
Remaining Recovery Period	2 years
AEP TEXAS INC. | Earns/earning a return | Approved for recovery | Meter Replacement Costs
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	$ 4	6
Remaining Recovery Period	2 years
AEP TEXAS INC. | Earns/earning a return | Approved for recovery | Other Regulatory Assets Approved for Recovery
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	$ 18	22
AEP TEXAS INC. | Does not earns/earning a return | Pending final regulatory approval
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	67	36
AEP TEXAS INC. | Does not earns/earning a return | Pending final regulatory approval | Storm-Related Costs
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	31	13
AEP TEXAS INC. | Does not earns/earning a return | Pending final regulatory approval | Deferred Pension and OPEB Costs
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	27	16
AEP TEXAS INC. | Does not earns/earning a return | Pending final regulatory approval | Other Regulatory Assets Pending Final Regulatory Approval
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	9	7
AEP TEXAS INC. | Does not earns/earning a return | Approved for recovery
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	172	216
AEP TEXAS INC. | Does not earns/earning a return | Approved for recovery | Other Regulatory Assets Approved for Recovery
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	4	15
AEP TEXAS INC. | Does not earns/earning a return | Approved for recovery | Pension and OPEB Funded Status
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	$ 155	178
Remaining Recovery Period	12 years
AEP TEXAS INC. | Does not earns/earning a return | Approved for recovery | Peak Demand Reduction/Energy Efficiency
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	$ 13	9
Remaining Recovery Period	2 years
AEP TEXAS INC. | Does not earns/earning a return | Approved for recovery | Texas Transmission Cost Recovery Factor
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	$ 0	$ 14