v3.25.2
RATE MATTERS - Net Book Value (Details) - Generating Units Probable of Abandonment - SWEPCo
$ in Millions
6 Months Ended
Jun. 30, 2025
USD ($)
Northeastern Plant, Unit 3  
Public Utilities, General Disclosures [Line Items]  
Net Book Value $ 79.8
Accelerated Depreciation Regulatory Asset 204.7
Cost of Removal Regulatory Liability 21.1
Depreciation 16.7
Welsh Plant, Units 1 and 3  
Public Utilities, General Disclosures [Line Items]  
Net Book Value 300.9
Accelerated Depreciation Regulatory Asset 192.7
Cost of Removal Regulatory Liability 57.7
Depreciation $ 45.9