v3.26.1
Employee Benefit Plans - SPPC (Details) - SPPC - United States - NV Energy, Inc. - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Other assets | Pension Plan    
Defined Benefit Plan Disclosure [Line Items]    
Other assets $ 74 $ 72
Other assets | Other Postretirement Plans    
Defined Benefit Plan Disclosure [Line Items]    
Other assets 2 2
Other current liabilities | Other Pension Plan    
Defined Benefit Plan Disclosure [Line Items]    
Other current liabilities (1) (1)
Other noncurrent liabilities | Other Pension Plan    
Defined Benefit Plan Disclosure [Line Items]    
Other long-term liabilities $ (5) $ (5)