BUSINESS SEGMENTS - AEP's Reportable Segment Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Revenues from:
Total Revenues		$ 21,876	$ 19,721	$ 18,982
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation		7,031	5,936	6,578
Other Operation and Maintenance		4,449	4,452	4,087
Asset Impairments and Other Related Charges	$ 66	66	143	86
Loss on the Sale of the Competitive Contracted Renewables Portfolio		0	0	93
Depreciation and Amortization		3,380	3,290	3,090
Taxes Other Than Income Taxes		1,631	1,596	1,492
Allowance for Equity Funds Used During Construction		245	211	175
Interest Expense		2,026	1,863	1,807
Income Tax Expense		129	(39)	55
Equity Earnings (Loss) of Unconsolidated Subsidiaries		101	94	59
Other Segment Items		(70)	(182)	(280)
EARNINGS ATTRIBUTABLE TO AEP MEMBER, Basic		3,580	2,967	2,208
EARNINGS ATTRIBUTABLE TO AEP MEMBER, Diluted		3,580	2,967	2,208
Gross Property Additions		11,906	8,030	7,533
Total Assets	114,460	114,460	103,078
Investments in Equity Method Investees	1,252	1,252	1,056	1,074
Nonrelated Party
Revenues from:
Total Revenues		21,876	19,721	18,982
Related Party
Revenues from:
Total Revenues		0	0	0
Operating Segments
Revenues from:
Total Revenues		24,105	21,501	20,524
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation		7,324	6,247	6,853
Other Operation and Maintenance		6,479	5,987	5,434
Asset Impairments and Other Related Charges		66	143	86
Loss on the Sale of the Competitive Contracted Renewables Portfolio				93
Depreciation and Amortization		3,400	3,312	3,107
Taxes Other Than Income Taxes		1,606	1,576	1,477
Allowance for Equity Funds Used During Construction		245	211	175
Interest Expense		1,529	1,369	1,408
Income Tax Expense		250	114	138
Equity Earnings (Loss) of Unconsolidated Subsidiaries		90	100	67
Other Segment Items		(83)	(194)	(296)
EARNINGS ATTRIBUTABLE TO AEP MEMBER, Basic		3,869	3,258	2,466
EARNINGS ATTRIBUTABLE TO AEP MEMBER, Diluted		3,869	3,258	2,466
Gross Property Additions		11,938	7,595	7,496
Total Assets	112,772	112,772	101,507
Investments in Equity Method Investees	1,081	1,081	1,007	1,020
Operating Segments | Nonrelated Party
Revenues from:
Total Revenues		21,843	19,664	18,921
Operating Segments | Related Party
Revenues from:
Total Revenues		2,262	1,837	1,603
Corporate and Other
Revenues from:
Total Revenues		144	183	168
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation		0	0	0
Other Operation and Maintenance		74	137	103
Asset Impairments and Other Related Charges		0	0	0
Loss on the Sale of the Competitive Contracted Renewables Portfolio				0
Depreciation and Amortization		(20)	(22)	(17)
Taxes Other Than Income Taxes		1	0	0
Allowance for Equity Funds Used During Construction		0	0	0
Interest Expense		592	613	594
Income Tax Expense		(121)	(153)	(83)
Equity Earnings (Loss) of Unconsolidated Subsidiaries		11	(6)	(8)
Other Segment Items		(82)	(107)	(179)
EARNINGS ATTRIBUTABLE TO AEP MEMBER, Basic		(289)	(291)	(258)
EARNINGS ATTRIBUTABLE TO AEP MEMBER, Diluted		(289)	(291)	(258)
Gross Property Additions		38	467	36
Total Assets	6,733	6,733	5,551
Investments in Equity Method Investees	171	171	49	54
Corporate and Other | Nonrelated Party
Revenues from:
Total Revenues		33	57	61
Corporate and Other | Related Party
Revenues from:
Total Revenues		111	126	107
Reconciling Adjustments
Revenues from:
Total Revenues		(2,373)	(1,963)	(1,710)
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation		(293)	(311)	(275)
Other Operation and Maintenance		(2,104)	(1,672)	(1,450)
Asset Impairments and Other Related Charges		0	0	0
Loss on the Sale of the Competitive Contracted Renewables Portfolio				0
Depreciation and Amortization		0	0	0
Taxes Other Than Income Taxes		24	20	15
Allowance for Equity Funds Used During Construction		0	0	0
Interest Expense		(95)	(119)	(195)
Income Tax Expense		0	0	0
Equity Earnings (Loss) of Unconsolidated Subsidiaries		0	0	0
Other Segment Items		95	119	195
EARNINGS ATTRIBUTABLE TO AEP MEMBER, Basic		0	0	0
EARNINGS ATTRIBUTABLE TO AEP MEMBER, Diluted		0	0	0
Gross Property Additions		(70)	(32)	1
Total Assets	(5,045)	(5,045)	(3,980)
Investments in Equity Method Investees	0	0	0	0
Reconciling Adjustments | Nonrelated Party
Revenues from:
Total Revenues		0	0	0
Reconciling Adjustments | Related Party
Revenues from:
Total Revenues		(2,373)	(1,963)	(1,710)
VIU | Operating Segments
Revenues from:
Total Revenues		12,819	11,597	11,450
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation		4,056	3,796	4,150
Other Operation and Maintenance		3,884	3,528	3,211
Asset Impairments and Other Related Charges		35	14	86
Loss on the Sale of the Competitive Contracted Renewables Portfolio				0
Depreciation and Amortization		2,076	1,971	1,876
Taxes Other Than Income Taxes		532	535	513
Allowance for Equity Funds Used During Construction		74	52	46
Interest Expense		856	724	765
Income Tax Expense		(60)	(282)	(45)
Equity Earnings (Loss) of Unconsolidated Subsidiaries		1	1	1
Other Segment Items		(90)	(89)	(149)
EARNINGS ATTRIBUTABLE TO AEP MEMBER, Basic		1,605	1,453	1,090
EARNINGS ATTRIBUTABLE TO AEP MEMBER, Diluted		1,605	1,453	1,090
Gross Property Additions		7,333	3,644	3,487
Total Assets	61,778	61,778	54,997
Investments in Equity Method Investees	9	9	9	10
VIU | Operating Segments | Nonrelated Party
Revenues from:
Total Revenues		12,556	11,414	11,304
VIU | Operating Segments | Related Party
Revenues from:
Total Revenues		263	183	146
T&D | Operating Segments
Revenues from:
Total Revenues		6,147	5,908	5,713
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation		943	909	1,215
Other Operation and Maintenance		2,318	2,166	1,948
Asset Impairments and Other Related Charges		31	53	0
Loss on the Sale of the Competitive Contracted Renewables Portfolio				0
Depreciation and Amortization		821	880	785
Taxes Other Than Income Taxes		744	724	668
Allowance for Equity Funds Used During Construction		77	69	46
Interest Expense		424	406	364
Income Tax Expense		173	155	140
Equity Earnings (Loss) of Unconsolidated Subsidiaries		2	(1)	0
Other Segment Items		(44)	(43)	(60)
EARNINGS ATTRIBUTABLE TO AEP MEMBER, Basic		816	726	699
EARNINGS ATTRIBUTABLE TO AEP MEMBER, Diluted		816	726	699
Gross Property Additions		2,978	2,344	2,467
Total Assets	29,272	29,272	26,864
Investments in Equity Method Investees	4	4	2	3
T&D | Operating Segments | Nonrelated Party
Revenues from:
Total Revenues		6,097	5,880	5,677
T&D | Operating Segments | Related Party
Revenues from:
Total Revenues		50	28	36
AEPTHCo | Operating Segments
Revenues from:
Total Revenues		2,377	1,951	1,729
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation		0	0	0
Other Operation and Maintenance		194	163	142
Asset Impairments and Other Related Charges		0	0	0
Loss on the Sale of the Competitive Contracted Renewables Portfolio				0
Depreciation and Amortization		487	440	403
Taxes Other Than Income Taxes		328	315	290
Allowance for Equity Funds Used During Construction		94	90	83
Interest Expense		241	222	203
Income Tax Expense		42	215	166
Equity Earnings (Loss) of Unconsolidated Subsidiaries		87	99	83
Other Segment Items		105	(5)	(12)
EARNINGS ATTRIBUTABLE TO AEP MEMBER, Basic		1,161	790	703
EARNINGS ATTRIBUTABLE TO AEP MEMBER, Diluted		1,161	790	703
Gross Property Additions		1,615	1,572	1,529
Total Assets	19,719	19,719	18,012
Investments in Equity Method Investees	1,068	1,068	996	906
AEPTHCo | Operating Segments | Nonrelated Party
Revenues from:
Total Revenues		493	425	397
AEPTHCo | Operating Segments | Related Party
Revenues from:
Total Revenues		1,884	1,526	1,332
G&M | Operating Segments
Revenues from:
Total Revenues		2,762	2,045	1,632
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation		2,325	1,542	1,488
Other Operation and Maintenance		83	130	133
Asset Impairments and Other Related Charges		0	76	0
Loss on the Sale of the Competitive Contracted Renewables Portfolio				93
Depreciation and Amortization		16	21	43
Taxes Other Than Income Taxes		2	2	6
Allowance for Equity Funds Used During Construction		0	0	0
Interest Expense		8	17	76
Income Tax Expense		95	26	(123)
Equity Earnings (Loss) of Unconsolidated Subsidiaries		0	1	(17)
Other Segment Items		(54)	(57)	(75)
EARNINGS ATTRIBUTABLE TO AEP MEMBER, Basic		287	289	(26)
EARNINGS ATTRIBUTABLE TO AEP MEMBER, Diluted		287	289	(26)
Gross Property Additions		12	35	13
Total Assets	2,003	2,003	1,634
Investments in Equity Method Investees	$ 0	0	0	101
G&M | Operating Segments | Nonrelated Party
Revenues from:
Total Revenues		2,697	1,945	1,543
G&M | Operating Segments | Related Party
Revenues from:
Total Revenues		$ 65	$ 100	$ 89