v3.26.1
ACQUISITIONS, DISPOSITIONS AND IMPAIRMENTS - Impact of Asset Acquisitions (Details)
MW in Millions, $ in Millions
 1 Months Ended 6 Months Ended
May 31, 2026
USD ($)
MW
Mar. 31, 2026
USD ($)
MW
Jun. 30, 2025
USD ($)
MW
Jun. 30, 2026
USD ($)
Dec. 31, 2025
USD ($)
Asset Acquisition, Contingent Consideration [Line Items]          
Property, Plant and Equipment, Net       $ 96,673 $ 92,374
Operating Lease Assets       642 661
Asset Retirement Obligations       3,645 3,556
Regulatory Liabilities and Deferred Investment Tax Credits       8,622 8,362
Other Current Liabilities       2,187 1,898
Deferred credits and other noncurrent liabilities       1,313 905
APPALACHIAN POWER COMPANY          
Asset Acquisition, Contingent Consideration [Line Items]          
Property, Plant and Equipment, Net       14,062 14,713
Operating Lease Assets       97 95
Asset Retirement Obligations       741 707
Regulatory Liabilities and Deferred Investment Tax Credits       1,064 1,111
Other Current Liabilities       297 271
Deferred credits and other noncurrent liabilities       47 45
INDIANA MICHIGAN POWER COMPANY          
Asset Acquisition, Contingent Consideration [Line Items]          
Property, Plant and Equipment, Net       9,040 7,944
Operating Lease Assets       46 52
Asset Retirement Obligations       2,208 2,165
Regulatory Liabilities and Deferred Investment Tax Credits       3,317 2,938
Other Current Liabilities       217 230
Deferred credits and other noncurrent liabilities       66 89
PUBLIC SERVICE COMPANY OF OKLAHOMA          
Asset Acquisition, Contingent Consideration [Line Items]          
Net Maximum Capacity | MW     1,228    
Property, Plant and Equipment, Net     $ 1,504 9,422 8,964
Operating Lease Assets     16 122 126
Asset Retirement Obligations     15 157 136
Other Liabilities     $ 91    
Regulatory Liabilities and Deferred Investment Tax Credits       712 717
Other Current Liabilities       118 104
Deferred credits and other noncurrent liabilities       $ 162 $ 33
Grover Hill Wind Project | APPALACHIAN POWER COMPANY          
Asset Acquisition, Contingent Consideration [Line Items]          
Net Maximum Capacity | MW 143        
Property, Plant and Equipment, Net $ 361        
Operating Lease Assets 8        
Asset Retirement Obligations $ 1        
Oregon Clean Energy Center | INDIANA MICHIGAN POWER COMPANY          
Asset Acquisition, Contingent Consideration [Line Items]          
Net Maximum Capacity | MW   870      
Property, Plant and Equipment, Net   $ 918      
Prepayments and Other Current Assets   35      
Materials and Supplies   5      
Accounts Receivable   16      
Accounts Payable   $ 9      
Pixley Solar Energy, LLC | PUBLIC SERVICE COMPANY OF OKLAHOMA          
Asset Acquisition, Contingent Consideration [Line Items]          
Net Maximum Capacity | MW     189    
Property, Plant and Equipment, Net     $ 380    
Operating Lease Assets     9    
Asset Retirement Obligations     12    
Other Liabilities     $ 0    
Flat Ridge IV Wind, LLC | PUBLIC SERVICE COMPANY OF OKLAHOMA          
Asset Acquisition, Contingent Consideration [Line Items]          
Net Maximum Capacity | MW     135    
Property, Plant and Equipment, Net     $ 305    
Operating Lease Assets     7    
Asset Retirement Obligations     3    
Other Liabilities     $ 0    
Green Country Energy, LLC | PUBLIC SERVICE COMPANY OF OKLAHOMA          
Asset Acquisition, Contingent Consideration [Line Items]          
Net Maximum Capacity | MW     904    
Property, Plant and Equipment, Net     $ 819    
Operating Lease Assets     0    
Asset Retirement Obligations     0    
Other Liabilities     91    
Regulatory Liabilities and Deferred Investment Tax Credits     50    
Other Current Liabilities     21    
Deferred credits and other noncurrent liabilities     $ 20