RATE MATTERS - FERC Rate Matters (Details) $ in Millions	1 Months Ended
	Oct. 31, 2023 USD ($)	Sep. 30, 2025 USD ($)	Jun. 30, 2025 order	Jan. 31, 2024 order
Public Utilities, General Disclosures [Line Items]
Number of order FERC issues | order			2	2
Independence Energy Connection Project
Public Utilities, General Disclosures [Line Items]
Aep share of independence energy connection capital costs		$ 91
Request to Update SWEPCo Generation Depreciation Rates
Public Utilities, General Disclosures [Line Items]
Requested annual revenue requirement	$ 5