BUSINESS SEGMENTS - Narrative (Details)	12 Months Ended
	Dec. 31, 2025 segment company
Segment Reporting Information [Line Items]
Number of reportable segments	1
AEP TEXAS INC.
Segment Reporting Information [Line Items]
Number of reportable segments	1
APPALACHIAN POWER COMPANY
Segment Reporting Information [Line Items]
Number of reportable segments	1
INDIANA MICHIGAN POWER COMPANY
Segment Reporting Information [Line Items]
Number of reportable segments	1
OHIO POWER COMPANY
Segment Reporting Information [Line Items]
Number of reportable segments	1
PUBLIC SERVICE COMPANY OF OKLAHOMA
Segment Reporting Information [Line Items]
Number of reportable segments	1
SOUTHWESTERN ELECTRIC POWER COMPANY
Segment Reporting Information [Line Items]
Number of reportable segments	1
AEP TRANSMISSION COMPANY, LLC
Segment Reporting Information [Line Items]
Number of reportable segments	1
Number of FERC-regulated transmission-only electric utilities | company	7
Number of operating segments	7