v3.25.1
Stockholders' Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax $ 93 $ (77)
Agency Securities [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Beginning OCI Balance (591) (517)
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax 93 (77)
Amounts reclassified from accumulated OCI 0 0
Ending OCI Balance $ (498) $ (594)