BENEFIT PLANS - Schedule of Expected Benefit Payments (Details) $ in Millions	Dec. 31, 2025 USD ($)
Pension Plans
Pension Plans and OPEB Benefit Payments
2026	$ 357
2027	352
2028	352
2029	342
2030	331
Years 2031 to 2035, in Total	1,573
Pension Plans \| AEP TEXAS INC.
Pension Plans and OPEB Benefit Payments
2026	35
2027	32
2028	32
2029	31
2030	29
Years 2031 to 2035, in Total	127
Pension Plans \| APPALACHIAN POWER COMPANY
Pension Plans and OPEB Benefit Payments
2026	43
2027	42
2028	41
2029	41
2030	40
Years 2031 to 2035, in Total	189
Pension Plans \| INDIANA MICHIGAN POWER COMPANY
Pension Plans and OPEB Benefit Payments
2026	42
2027	41
2028	41
2029	38
2030	38
Years 2031 to 2035, in Total	182
Pension Plans \| OHIO POWER COMPANY
Pension Plans and OPEB Benefit Payments
2026	32
2027	32
2028	31
2029	30
2030	29
Years 2031 to 2035, in Total	139
Pension Plans \| PUBLIC SERVICE COMPANY OF OKLAHOMA
Pension Plans and OPEB Benefit Payments
2026	18
2027	17
2028	18
2029	16
2030	16
Years 2031 to 2035, in Total	76
Pension Plans \| SOUTHWESTERN ELECTRIC POWER COMPANY
Pension Plans and OPEB Benefit Payments
2026	21
2027	21
2028	21
2029	20
2030	20
Years 2031 to 2035, in Total	95
OPEB
Pension Plans and OPEB Benefit Payments
2026	111
2027	110
2028	108
2029	105
2030	104
Years 2031 to 2035, in Total	486
OPEB Medicare Subsidy Receipts
2026	0
2027	0
2028	0
2028	0
2030	0
Years 2031 to 2035, in Total	1
OPEB \| AEP TEXAS INC.
Pension Plans and OPEB Benefit Payments
2026	9
2027	9
2028	9
2029	9
2030	8
Years 2031 to 2035, in Total	39
OPEB Medicare Subsidy Receipts
2026	0
2027	0
2028	0
2028	0
2030	0
Years 2031 to 2035, in Total	0
OPEB \| APPALACHIAN POWER COMPANY
Pension Plans and OPEB Benefit Payments
2026	17
2027	17
2028	17
2029	17
2030	16
Years 2031 to 2035, in Total	75
OPEB Medicare Subsidy Receipts
2026	0
2027	0
2028	0
2028	0
2030	0
Years 2031 to 2035, in Total	0
OPEB \| INDIANA MICHIGAN POWER COMPANY
Pension Plans and OPEB Benefit Payments
2026	14
2027	14
2028	13
2029	13
2030	13
Years 2031 to 2035, in Total	59
OPEB Medicare Subsidy Receipts
2026	0
2027	0
2028	0
2028	0
2030	0
Years 2031 to 2035, in Total	0
OPEB \| OHIO POWER COMPANY
Pension Plans and OPEB Benefit Payments
2026	11
2027	11
2028	11
2029	10
2030	10
Years 2031 to 2035, in Total	48
OPEB Medicare Subsidy Receipts
2026	0
2027	0
2028	0
2028	0
2030	0
Years 2031 to 2035, in Total	0
OPEB \| PUBLIC SERVICE COMPANY OF OKLAHOMA
Pension Plans and OPEB Benefit Payments
2026	6
2027	6
2028	6
2029	6
2030	6
Years 2031 to 2035, in Total	27
OPEB Medicare Subsidy Receipts
2026	0
2027	0
2028	0
2028	0
2030	0
Years 2031 to 2035, in Total	0
OPEB \| SOUTHWESTERN ELECTRIC POWER COMPANY
Pension Plans and OPEB Benefit Payments
2026	8
2027	8
2028	8
2029	7
2030	7
Years 2031 to 2035, in Total	35
OPEB Medicare Subsidy Receipts
2026	0
2027	0
2028	0
2028	0
2030	0
Years 2031 to 2035, in Total	$ 0

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