v3.25.1
Investment Securities (Summary Of Changes In Accumulated OCI For Available-For-Sale Security) (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Accumulated Other Comprehensive Income (Loss) [Roll Forward]    
Unrealized Gains and (Losses), Net $ 93 $ (77)
Agency Securities [Member]    
Accumulated Other Comprehensive Income (Loss) [Roll Forward]    
Beginning OCI Balance (591) (517)
Unrealized Gains and (Losses), Net 93 (77)
Reversal of Unrealized (Gains) and Losses, Net on Realization 0 0
Ending OCI Balance $ (498) $ (594)