PROPERTY, PLANT AND EQUIPMENT - Total Plant Balances (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Property, Plant and Equipment [Line Items]
Generation	$ 28,252	$ 24,695
Transmission	42,557	38,871
Distribution	33,364	31,062
Other	7,731	6,545
CWIP	7,613	6,322
Less: Accumulated Depreciation	27,879	25,794
Total Regulated Property, Plant and Equipment - Net	91,638	81,701
Nonregulated Property, Plant and Equipment - Net	736	715
TOTAL PROPERTY, PLANT AND EQUIPMENT – NET	92,374	82,416
AEP Texas
Property, Plant and Equipment [Line Items]
Generation	0	0
Transmission	8,229	7,547
Distribution	6,835	6,250
Other	1,236	1,173
CWIP	1,766	1,118
Less: Accumulated Depreciation	2,204	2,046
Total Regulated Property, Plant and Equipment - Net	15,862	14,042
Nonregulated Property, Plant and Equipment - Net	2	2
TOTAL PROPERTY, PLANT AND EQUIPMENT – NET	15,864	14,044
AEP TRANSMISSION COMPANY, LLC
Property, Plant and Equipment [Line Items]
Generation	0	0
Transmission	16,542	14,913
Distribution	0	0
Other	571	516
CWIP	2,005	1,965
Less: Accumulated Depreciation	1,915	1,578
Total Regulated Property, Plant and Equipment - Net	17,203	15,816
Nonregulated Property, Plant and Equipment - Net	0	0
TOTAL PROPERTY, PLANT AND EQUIPMENT – NET	17,203	15,816
APPALACHIAN POWER COMPANY
Property, Plant and Equipment [Line Items]
Generation	7,886	7,273
Transmission	5,277	5,001
Distribution	5,938	5,569
Other	1,127	1,023
CWIP	802	743
Less: Accumulated Depreciation	6,360	6,031
Total Regulated Property, Plant and Equipment - Net	14,670	13,578
Nonregulated Property, Plant and Equipment - Net	43	35
TOTAL PROPERTY, PLANT AND EQUIPMENT – NET	14,713	13,613
INDIANA MICHIGAN POWER COMPANY
Property, Plant and Equipment [Line Items]
Generation	5,415	5,439
Transmission	2,055	1,958
Distribution	3,823	3,535
Other	1,011	947
CWIP	397	330
Less: Accumulated Depreciation	4,829	4,607
Total Regulated Property, Plant and Equipment - Net	7,872	7,602
Nonregulated Property, Plant and Equipment - Net	72	77
TOTAL PROPERTY, PLANT AND EQUIPMENT – NET	7,944	7,679
OHIO POWER COMPANY
Property, Plant and Equipment [Line Items]
Generation	0	0
Transmission	3,916	3,664
Distribution	7,661	7,244
Other	1,277	1,245
CWIP	811	691
Less: Accumulated Depreciation	2,992	2,883
Total Regulated Property, Plant and Equipment - Net	10,673	9,961
Nonregulated Property, Plant and Equipment - Net	11	10
TOTAL PROPERTY, PLANT AND EQUIPMENT – NET	10,684	9,971
PUBLIC SERVICE COMPANY OF OKLAHOMA
Property, Plant and Equipment [Line Items]
Generation	4,365	2,772
Transmission	1,433	1,345
Distribution	3,987	3,699
Other	1,289	547
CWIP	635	379
Less: Accumulated Depreciation	2,749	2,215
Total Regulated Property, Plant and Equipment - Net	8,960	6,527
Nonregulated Property, Plant and Equipment - Net	4	5
TOTAL PROPERTY, PLANT AND EQUIPMENT – NET	8,964	6,532
SOUTHWESTERN ELECTRIC POWER COMPANY
Property, Plant and Equipment [Line Items]
Generation	6,621	5,288
Transmission	3,302	2,864
Distribution	3,242	3,007
Other	726	683
CWIP	712	627
Less: Accumulated Depreciation	3,288	3,049
Total Regulated Property, Plant and Equipment - Net	11,315	9,420
Nonregulated Property, Plant and Equipment - Net	26	26
TOTAL PROPERTY, PLANT AND EQUIPMENT – NET	$ 11,341	$ 9,446