v3.25.1
Pledged Assets (Assets Pledged as Collateral) (Details) - USD ($)
$ in Millions
Mar. 31, 2025
Dec. 31, 2024
Mar. 31, 2024
Offsetting Assets and Liabilities [Line Items]      
Accrued interest on pledged securities $ 305 $ 280  
Restricted cash 1,263 1,266 $ 1,368
Total Fair Value of Securities Pledged and Accrued Interest 69,916    
Total Fair Value Of Agency Securities Pledged And Accrued Interest   63,989  
Security Owned and Pledged as Collateral, Fair Value 67,750 62,168  
Retained Interests in Consolidated VIE's Pledged as Collateral Under Repurchase Agreements 33 33  
Repurchase Agreements [Member]      
Offsetting Assets and Liabilities [Line Items]      
Security Owned and Pledged as Collateral, Fair Value 64,116 59,958  
Derivative Agreements and Other      
Offsetting Assets and Liabilities [Line Items]      
Total Fair Value of Securities Pledged and Accrued Interest 1,392 1,059  
Security Owned and Pledged as Collateral, Fair Value 100 27  
Repurchase Agreements [Member]      
Offsetting Assets and Liabilities [Line Items]      
Accrued interest on pledged securities 296 279  
Total Fair Value of Securities Pledged and Accrued Interest 68,429    
Total Fair Value Of Agency Securities Pledged And Accrued Interest   62,833  
Variable Interest Entity, Primary Beneficiary [Member]      
Offsetting Assets and Liabilities [Line Items]      
Accrued interest on pledged securities 0 0  
Total Fair Value of Securities Pledged and Accrued Interest 95    
Total Fair Value Of Agency Securities Pledged And Accrued Interest   97  
Security Owned and Pledged as Collateral, Fair Value 95 97  
Includes Sold But Not Yet Settled Securities [Member]      
Offsetting Assets and Liabilities [Line Items]      
Security Owned and Pledged as Collateral, Fair Value 64,311 60,082  
Credit Risk Transfer Securities [Member]      
Offsetting Assets and Liabilities [Line Items]      
Security Owned and Pledged as Collateral, Fair Value 595 590  
Credit Risk Transfer Securities [Member] | Repurchase Agreements [Member]      
Offsetting Assets and Liabilities [Line Items]      
Security Owned and Pledged as Collateral, Fair Value 595 590  
Non-Agency [Member]      
Offsetting Assets and Liabilities [Line Items]      
Security Owned and Pledged as Collateral, Fair Value 173 206  
Non-Agency [Member] | Repurchase Agreements [Member]      
Offsetting Assets and Liabilities [Line Items]      
Security Owned and Pledged as Collateral, Fair Value 173 206  
US Treasury Securities [Member]      
Offsetting Assets and Liabilities [Line Items]      
Security Owned and Pledged as Collateral, Fair Value 3,269 1,565  
US Treasury Securities [Member] | Repurchase Agreements [Member]      
Offsetting Assets and Liabilities [Line Items]      
Security Owned and Pledged as Collateral, Fair Value 2,866 1,414  
US Treasury Securities [Member] | Derivative Agreements and Other      
Offsetting Assets and Liabilities [Line Items]      
Security Owned and Pledged as Collateral, Fair Value 403 151  
Derivative Agreements and Other      
Offsetting Assets and Liabilities [Line Items]      
Accrued interest on pledged securities 9 1  
Repurchase Agreements [Member]      
Offsetting Assets and Liabilities [Line Items]      
Restricted cash 383 386  
Excluding Cash Received [Member]      
Offsetting Assets and Liabilities [Line Items]      
Restricted cash 1,263 1,266  
Derivative Agreements and Other      
Offsetting Assets and Liabilities [Line Items]      
Restricted cash $ 880 $ 880