v3.25.2
Fair Value Measurements (Quantitative Level 3 Fair Value Disclosures) (Details)
$ in Millions
Jun. 30, 2025
USD ($)
$ / MWh
Mar. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
$ / MWh
Jun. 30, 2024
USD ($)
Mar. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Fair Value Measurement Inputs and Valuation Techniques            
Net derivative asset (liability) | $ $ 14 $ 3 $ 9 $ 35 $ 6 $ 15
Duke Energy Ohio | FTRs | RTO auction pricing            
Fair Value Measurement Inputs and Valuation Techniques            
Net derivative asset (liability) | $ $ 1   $ 1      
Duke Energy Ohio | FTRs | RTO auction pricing | Minimum            
Fair Value Measurement Inputs and Valuation Techniques            
Input measurements (in usd per MWh and usd per MMBtu) 0   0      
Duke Energy Ohio | FTRs | RTO auction pricing | Maximum            
Fair Value Measurement Inputs and Valuation Techniques            
Input measurements (in usd per MWh and usd per MMBtu) 0.78   1.13      
Duke Energy Ohio | FTRs | RTO auction pricing | Weighted Average            
Fair Value Measurement Inputs and Valuation Techniques            
Input measurements (in usd per MWh and usd per MMBtu) 0.20   0.48      
Duke Energy Indiana            
Fair Value Measurement Inputs and Valuation Techniques            
Net derivative asset (liability) | $ $ 13 $ 2 $ 8 $ 33 $ 5 $ 13
Duke Energy Indiana | FTRs | RTO auction pricing            
Fair Value Measurement Inputs and Valuation Techniques            
Net derivative asset (liability) | $ $ 13   $ 8      
Duke Energy Indiana | FTRs | RTO auction pricing | Minimum            
Fair Value Measurement Inputs and Valuation Techniques            
Input measurements (in usd per MWh and usd per MMBtu) (2.09)   (0.63)      
Duke Energy Indiana | FTRs | RTO auction pricing | Maximum            
Fair Value Measurement Inputs and Valuation Techniques            
Input measurements (in usd per MWh and usd per MMBtu) 17.87   9.24      
Duke Energy Indiana | FTRs | RTO auction pricing | Weighted Average            
Fair Value Measurement Inputs and Valuation Techniques            
Input measurements (in usd per MWh and usd per MMBtu) 0.95   0.94