v3.26.1
Accumulated Other Comprehensive Income (Changes In The Components Of AOCI) (Detail) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Beginning balance $ (2,237)  
Other comprehensive income (loss) (8) $ 29
Ending balance (2,283)  
Accumulated Other Comprehensive Income [Member]    
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Beginning balance (95)  
Other comprehensive income (loss) (8)  
Ending balance (103)  
Unrealized gains (losses) on AFS, net [Member]    
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Beginning balance (114)  
Other comprehensive income (loss) (9)  
Ending balance (123)  
Instrument-specific credit risk of liabilities measured at fair value, net [Member]    
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Beginning balance 19  
Other comprehensive income (loss) 1  
Ending balance 20  
Instrument-specific credit risk of liabilities measured at fair value, net [Member] | Accumulated Other Comprehensive Income [Member]    
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Beginning balance 19  
Ending balance $ 20