v3.25.2
Stockholders' Equity - Components of AOCI (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Mar. 31, 2025
Dec. 31, 2024
Jun. 30, 2024
Mar. 31, 2024
Dec. 31, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]            
Total Equity $ 1,246 $ 1,180 $ 1,387 $ 2,572 $ 2,766 $ 2,534
Accumulated other comprehensive income (loss)            
Accumulated Other Comprehensive Income (Loss) [Line Items]            
Total Equity (9) $ (10) $ (12) (29) $ (27) $ (23)
Available-for-sale securities unrealized gain (loss), net            
Accumulated Other Comprehensive Income (Loss) [Line Items]            
Total Equity 1     (1)    
Postretirement benefit prior service credits (costs), net            
Accumulated Other Comprehensive Income (Loss) [Line Items]            
Total Equity 13     0    
Postretirement benefit actuarial gain (loss), net            
Accumulated Other Comprehensive Income (Loss) [Line Items]            
Total Equity $ (23)     $ (28)