v3.26.1
Mortgage Loans - Amortized Cost Basis of Multifamily Held-for-Investment Loans by Credit Quality Indicator by Vintage (Details) - USD ($)
$ in Millions
 6 Months Ended 12 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Financing Receivable, Credit Quality Indicator [Line Items]    
Current fiscal year, year-to-date write-offs $ 0 $ 1
Fiscal year before current fiscal year, year-to-date write-offs 7 22
Two years before current fiscal Year, year-to-date write-offs 49 44
Three years before current fiscal year, year-to-date write-offs 80 75
Four years before current fiscal year, year-to-date write-offs 86 55
Total 3,332,768 3,291,359
Total current-year gross charge-offs 288 371
Multifamily    
Financing Receivable, Credit Quality Indicator [Line Items]    
Current fiscal year 26,066 63,205
Current fiscal year, year-to-date write-offs 0 0
One year before current fiscal year 66,855 28,825
Fiscal year before current fiscal year, year-to-date write-offs 0 0
Two years before current fiscal year 28,598 13,813
Two years before current fiscal Year, year-to-date write-offs 0 0
Three years before current fiscal year 13,369 16,490
Three years before current fiscal year, year-to-date write-offs 0 11
Four years before current fiscal year 16,041 7,567
Four years before current fiscal year, year-to-date write-offs 2 0
Five years before current fiscal year 20,846 13,842
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff 50 115
Revolving Loans 1,313 1,851
Financing Receivable, Excluding Accrued Interest, Revolving, Writeoff 0 0
Total 173,088 145,593
Total current-year gross charge-offs 52 126
Pass | Multifamily    
Financing Receivable, Credit Quality Indicator [Line Items]    
Current fiscal year 26,066 63,205
One year before current fiscal year 66,740 28,613
Two years before current fiscal year 27,940 13,374
Three years before current fiscal year 12,658 15,732
Four years before current fiscal year 15,010 7,238
Five years before current fiscal year 19,831 12,947
Revolving Loans 1,313 1,851
Total 169,558 142,960
Special mention | Multifamily    
Financing Receivable, Credit Quality Indicator [Line Items]    
Current fiscal year 0 0
One year before current fiscal year 115 49
Two years before current fiscal year 267 173
Three years before current fiscal year 100 177
Four years before current fiscal year 185 96
Five years before current fiscal year 537 670
Revolving Loans 0 0
Total 1,204 1,165
Substandard | Multifamily    
Financing Receivable, Credit Quality Indicator [Line Items]    
Current fiscal year 0 0
One year before current fiscal year 0 163
Two years before current fiscal year 391 266
Three years before current fiscal year 611 581
Four years before current fiscal year 846 233
Five years before current fiscal year 478 225
Revolving Loans 0 0
Total 2,326 1,468
Doubtful | Multifamily    
Financing Receivable, Credit Quality Indicator [Line Items]    
Current fiscal year 0 0
One year before current fiscal year 0 0
Two years before current fiscal year 0 0
Three years before current fiscal year 0 0
Four years before current fiscal year 0 0
Five years before current fiscal year 0 0
Revolving Loans 0 0
Total $ 0 $ 0