FINANCING ACTIVITIES - Schedule of Utility Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits (Details) - Utility $ in Millions	6 Months Ended
Jun. 30, 2026 USD ($)
AEP TEXAS INC.
Short-Term Debt [Line Items]
Maximum Borrowings	$ 624
Maximum Loans	186
Average Borrowings	308
Average Loans	98
Authorized Short-term Borrowing Limit	750
AEP TEXAS INC. \| Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	(354)
AEP TRANSMISSION COMPANY, LLC
Short-Term Debt [Line Items]
Maximum Borrowings	205
Maximum Loans	342
Average Borrowings	46
Average Loans	72
Authorized Short-term Borrowing Limit	820
AEP TRANSMISSION COMPANY, LLC \| Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	10
APPALACHIAN POWER COMPANY
Short-Term Debt [Line Items]
Maximum Borrowings	594
Maximum Loans	648
Average Borrowings	199
Average Loans	24
Authorized Short-term Borrowing Limit	950
APPALACHIAN POWER COMPANY \| Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	(109)
INDIANA MICHIGAN POWER COMPANY
Short-Term Debt [Line Items]
Maximum Borrowings	146
Maximum Loans	855
Average Borrowings	37
Average Loans	159
Authorized Short-term Borrowing Limit	750
INDIANA MICHIGAN POWER COMPANY \| Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	63
OHIO POWER COMPANY
Short-Term Debt [Line Items]
Maximum Borrowings	198
Maximum Loans	42
Average Borrowings	95
Average Loans	17
Authorized Short-term Borrowing Limit	750
OHIO POWER COMPANY \| Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	(64)
PUBLIC SERVICE COMPANY OF OKLAHOMA
Short-Term Debt [Line Items]
Maximum Borrowings	505
Maximum Loans	0
Average Borrowings	348
Average Loans	0
Authorized Short-term Borrowing Limit	950
PUBLIC SERVICE COMPANY OF OKLAHOMA \| Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	(394)
SOUTHWESTERN ELECTRIC POWER COMPANY
Short-Term Debt [Line Items]
Maximum Borrowings	375
Maximum Loans	1,308
Average Borrowings	257
Average Loans	85
Authorized Short-term Borrowing Limit	950
SOUTHWESTERN ELECTRIC POWER COMPANY \| Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	$ (311)

Authorized Short-term Borrowing Limit by regulatory orders.

No definition available.

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- Definition

Average Borrowings from a Money Pool during the period. The Money Pool represents centralized funding mechanism AEP uses to meet the short-term cash requirements of certain subsidiaries.

+ References

No definition available.

+ Details

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- Definition

Average Loans to a Money Pool during the period. The Money Pool represents centralized funding mechanism AEP uses to meet the short-term cash requirements of certain subsidiaries.

+ References

No definition available.

+ Details

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- Definition

Maximum Borrowings from a Money Pool at anytime during the period. The Money Pool represents a centralized funding mechanism AEP uses to meet the short-term cash requirements of certain subsidiaries.

+ References

No definition available.

+ Details

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- Definition

Maximum Loans to a Money Pool at anytime during the period. The Money Pool represents centralized funding mechanism AEP uses to meet the short-term cash requirements of certain subsidiaries.

+ References

No definition available.

+ Details

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Balance Type:	debit
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- Definition

Net Loans To (Borrowings From) The Utility Money

+ References

No definition available.

+ Details

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Namespace Prefix:	aeptexas_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480657/210-10-S50-8

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

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Name:	dei_LegalEntityAxis=aeptexas_AppalachianPowerCompanyMember
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- Details

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