v3.26.1
Cover Page - shares
 6 Months Ended
Jun. 30, 2026
Jul. 30, 2026
Entity Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2026  
Document Transition Report false  
Entity File Number 1-3525  
Entity Registrant Name AEP TEXAS INC.  
Entity Incorporation, State or Country Code NY  
Entity Tax Identification Number 13-4922640  
Entity Address, Address Line One 1 Riverside Plaza,  
Entity Address, City or Town Columbus,  
Entity Address, State or Province OH  
Entity Address, Postal Zip Code 43215-2373  
City Area Code (614)  
Local Phone Number 716-1000  
Title of 12(b) Security Common Stock, $6.50 par value  
Trading Symbol AEP  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   544,397,352
Entity Central Index Key 0001721781  
Amendment Flag false  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q2  
Current Fiscal Year End Date --12-31  
AEP TEXAS INC.    
Entity Information [Line Items]    
Entity File Number 333-221643  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 51-0007707  
Entity Common Stock, Shares Outstanding   100
AEP TRANSMISSION COMPANY, LLC    
Entity Information [Line Items]    
Entity File Number 333-217143  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 46-1125168  
APPALACHIAN POWER COMPANY    
Entity Information [Line Items]    
Entity File Number 1-3457  
Entity Incorporation, State or Country Code VA  
Entity Tax Identification Number 54-0124790  
Entity Common Stock, Shares Outstanding   13,499,500
INDIANA MICHIGAN POWER COMPANY    
Entity Information [Line Items]    
Entity File Number 1-3570  
Entity Incorporation, State or Country Code IN  
Entity Tax Identification Number 35-0410455  
Entity Common Stock, Shares Outstanding   1,400,000
OHIO POWER COMPANY    
Entity Information [Line Items]    
Entity File Number 1-6543  
Entity Incorporation, State or Country Code OH  
Entity Tax Identification Number 31-4271000  
Entity Common Stock, Shares Outstanding   27,952,473
PUBLIC SERVICE COMPANY OF OKLAHOMA    
Entity Information [Line Items]    
Entity File Number 0-343  
Entity Incorporation, State or Country Code OK  
Entity Tax Identification Number 73-0410895  
Entity Common Stock, Shares Outstanding   9,013,000
SOUTHWESTERN ELECTRIC POWER COMPANY    
Entity Information [Line Items]    
Entity File Number 1-3146  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 72-0323455  
Entity Common Stock, Shares Outstanding   3,680