v3.25.1
Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Dec. 31, 2024
Dec. 31, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Stockholders' Equity Attributable to Parent $ 7,047 $ 6,780 $ 7,004 $ 6,668
Accumulated Defined Benefit Plans Adjustment        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Stockholders' Equity Attributable to Parent (5) (11) (5) (11)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent 0 0    
Accumulated Other Comprehensive Income/(Loss)        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Stockholders' Equity Attributable to Parent 82 27 63 (72)
Net change in fair value 19 99    
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent 19 99    
Available-for-sale Securities | AOCI Unrealized gain/loss, Available-for-sale        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Stockholders' Equity Attributable to Parent 87 38 $ 68 $ (61)
AFS Unrealized Gain/(Loss) on AFS Securities 19 99    
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent $ 19 $ 99