v3.26.1
Stockholders' Equity - Components of AOCI (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Total Equity $ 1,073 $ 1,093 $ 1,180 $ 1,387
Accumulated other comprehensive income (loss)        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Total Equity (11) $ (4) (10) $ (12)
Available-for-sale securities unrealized gain (loss), net        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Total Equity (4)   0  
Postretirement benefit prior service credits (costs), net        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Total Equity 11   13  
Postretirement benefit actuarial gain (loss), net        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Total Equity $ (18)   $ (23)