FINANCING ACTIVITIES - Schedule of Utility Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits (Details) - Utility $ in Millions	9 Months Ended
Sep. 30, 2026 USD ($)
AEP Texas
Short-Term Debt [Line Items]
Maximum Borrowings	$ 624
Maximum Loans	540
Average Borrowings	313
Average Loans	295
Authorized Short-term Borrowing Limit	750
AEP Texas \| Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	382
AEPTCo
Short-Term Debt [Line Items]
Maximum Borrowings	474
Maximum Loans	342
Average Borrowings	137
Average Loans	56
Authorized Short-term Borrowing Limit	1,070
AEPTCo \| Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	(196)
APCo
Short-Term Debt [Line Items]
Maximum Borrowings	594
Maximum Loans	648
Average Borrowings	154
Average Loans	21
Authorized Short-term Borrowing Limit	950
APCo \| Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	45
I&M
Short-Term Debt [Line Items]
Maximum Borrowings	283
Maximum Loans	855
Average Borrowings	180
Average Loans	147
Authorized Short-term Borrowing Limit	750
I&M \| Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	(284)
OPCo
Short-Term Debt [Line Items]
Maximum Borrowings	328
Maximum Loans	71
Average Borrowings	113
Average Loans	23
Authorized Short-term Borrowing Limit	750
OPCo \| Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	(240)
PSO
Short-Term Debt [Line Items]
Maximum Borrowings	508
Maximum Loans	818
Average Borrowings	354
Average Loans	332
Authorized Short-term Borrowing Limit	950
PSO \| Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	70
SWEPCo
Short-Term Debt [Line Items]
Maximum Borrowings	375
Maximum Loans	1,308
Average Borrowings	258
Average Loans	192
Authorized Short-term Borrowing Limit	950
SWEPCo \| Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	$ 494

Authorized Short-term Borrowing Limit by regulatory orders.

No definition available.

Name:	aep_AuthorizedShortTermBorrowingLimit
Namespace Prefix:	aep_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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

Name:	aep_AverageBorrowingsFromMoneyPool
Namespace Prefix:	aep_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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

Name:	aep_AverageLoansToMoneyPool
Namespace Prefix:	aep_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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

Name:	aep_MaximumBorrowingsFromMoneyPool
Namespace Prefix:	aep_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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

Name:	aep_MaximumLoansToMoneyPool
Namespace Prefix:	aep_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Net Loans To (Borrowings From) The Utility Money

+ References

No definition available.

+ Details

Name:	aep_NetLoansToBorrowingsFromTheUtilityMoney
Namespace Prefix:	aep_
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

+ Details

Name:	us-gaap_ShortTermDebtLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	aep_MoneyPoolParticipantbyCompanyTypeAxis=aep_UtilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=aep_AEPTexasInc.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=us-gaap_RelatedPartyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=aep_AEPTransmissionCompanyLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=aep_AppalachianPowerCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=aep_IndianaMichiganPowerCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=aep_OhioPowerCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=aep_PublicServiceCompanyOfOklahomaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=aep_SouthwesternElectricPowerCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: