v3.25.4
Short-Term and Long-Term Debt - Short-Term Debt (Details) - Fannie Mae - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Short-Term Debt [Line Items]    
Short-term debt of Fannie Mae, outstanding $ 24,538 $ 11,188
Short-term debt of Fannie Mae, weighted-average interest rate 3.66% 4.33%