Segment Reporting - Schedule of Assets by Segment (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 4,229,166	$ 3,985,749
Operating Segments | Single-Family
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	3,782,447	3,569,130
Operating Segments | Multifamily
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 446,719	$ 416,619