v3.26.1
Asset Retirement Obligations - Non-Nuclear Asset Retirement Obligations Rollforward (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
Accretion expense $ 174 $ 158
Nonnuclear Decommissioning Asset Retirement Obligation [Member]    
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
ARO beginning balance 317  
Acquisition of Calpine 350  
Accretion expense 9  
Costs incurred related to decommissioning plants (1)  
ARO ending balance $ 675