v3.26.1
Employee Benefit Plans - SPPC (Details) - SPPC - United States - NV Energy, Inc. - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Balance Sheet Location [Axis]: us-gaap:OtherAssetsNoncurrent | Pension Plan    
Defined Benefit Plan Disclosure [Line Items]    
Other assets $ 75 $ 72
Balance Sheet Location [Axis]: us-gaap:OtherAssetsNoncurrent | Other Postretirement Plans    
Defined Benefit Plan Disclosure [Line Items]    
Other assets 5 2
Balance Sheet Location [Axis]: us-gaap:OtherLiabilitiesCurrent | Other Pension Plan    
Defined Benefit Plan Disclosure [Line Items]    
Other current liabilities (1) (1)
Balance Sheet Location [Axis]: us-gaap:OtherLiabilitiesNoncurrent | Other Pension Plan    
Defined Benefit Plan Disclosure [Line Items]    
Other long-term liabilities $ (5) $ (5)