v3.25.2
Regulatory Matters (Regulatory Matters Narrative - Duke Energy Ohio) (Details) - USD ($)
$ in Millions
1 Months Ended
Jun. 02, 2025
May 15, 2024
Oct. 12, 2023
Dec. 31, 2024
Apr. 30, 2024
Apr. 30, 2023
Jun. 30, 2025
Duke Energy Ohio Gas Base Rate Case | PUCO | Duke Energy Ohio              
Public Utilities, General Disclosures [Line Items]              
Requested rate increase (decrease), amount           $ 32  
Equity ratio (as a percent)           52.32%  
Requested return on equity (as a percent)           9.60%  
Duke Energy Ohio Energy Security Plan | PUCO | Duke Energy Ohio              
Public Utilities, General Disclosures [Line Items]              
Settlement rate, period (in years)   3 years     3 years    
Regulatory assets       $ 30     $ 6
Duke Energy Kentucky Electric Base Rate Case | KPSC | Duke Energy Ohio              
Public Utilities, General Disclosures [Line Items]              
Equity ratio (as a percent)     52.145%        
Approved rate increase (decrease), amount     $ 48        
Duke Energy Kentucky Electric Base Rate Case, Electric Base Rates | KPSC | Duke Energy Ohio              
Public Utilities, General Disclosures [Line Items]              
Approved return on equity percentage (as a percent)     9.75%        
Duke Energy Kentucky Electric Base Rate Case, Electric Riders | KPSC | Duke Energy Ohio              
Public Utilities, General Disclosures [Line Items]              
Approved return on equity percentage (as a percent)     9.65%        
Duke Energy Kentucky 2024 Electric Base Rate Case | KPSC | Duke Energy Kentucky              
Public Utilities, General Disclosures [Line Items]              
Requested rate increase (decrease), amount       $ 70      
Equity ratio (as a percent)       52.728%      
Requested return on equity (as a percent)       10.85%      
Requested rate increase, percentage, net of tax       14.70%      
Duke Energy Kentucky 2025 Natural Gas Base Rate Case | KPSC | Duke Energy Kentucky              
Public Utilities, General Disclosures [Line Items]              
Requested rate increase (decrease), amount $ 26            
Equity ratio (as a percent) 52.649%            
Requested return on equity (as a percent) 10.75%            
Requested rate increase, percentage, net of tax 17.00%