Segment Reporting - Schedule of Assets by Segment (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Segment Reporting [Line Items]
Total assets	$ 4,317,887	$ 4,317,538
Business segments | Single-Family
Segment Reporting [Line Items]
Total assets	3,740,283	3,757,261
Business segments | Multifamily
Segment Reporting [Line Items]
Total assets	$ 577,604	$ 560,277