FINANCING ACTIVITIES - Schedule of Direct Borrowing Activity (Details) - Direct Borrowing $ in Millions	3 Months Ended
Mar. 31, 2026 USD ($)
AEP TRANSMISSION COMPANY, LLC
Short-Term Debt [Line Items]
Maximum Borrowings	$ 0
Maximum Loans	302
Average Borrowings	0
Average Loans	147
Borrowings	0
Loans	161
Authorized Short-term Borrowing Limit	0
SWTCo
Short-Term Debt [Line Items]
Maximum Borrowings	2
Maximum Loans	0
Average Borrowings	2
Average Loans	0
Borrowings	2
Loans	0
Authorized Short-term Borrowing Limit	$ 50

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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Balance Type:	debit
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- Definition

Borrowings from Parent at period end. Parent represents centralized funding mechanism AEP uses to meet the short-term cash requirements of certain subsidiaries.

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No definition available.

+ Details

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- Definition

Loans to Parent at period end. Parent 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
Period Type:	duration

- 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

No definition available.

+ Details

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