Guarantees and Other Off-Balance Sheet Credit Exposures - UPB of Loans Underlying Our Mortgage-Related Guarantees by Payment Status (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Guarantor Obligations [Line Items]
Current	$ 373,214	$ 397,437
One Month Past Due	2,375	2,518
Two Months Past Due	1,078	969
Three Months or More Past Due, or in Foreclosure	3,145	3,009
Total	379,812	403,933
Single Family
Guarantor Obligations [Line Items]
Current	32,713	33,454
One Month Past Due	2,234	2,183
Two Months Past Due	860	852
Three Months or More Past Due, or in Foreclosure	1,430	1,490
Total	37,237	37,979
Multifamily
Guarantor Obligations [Line Items]
Current	340,501	363,983
One Month Past Due	141	335
Two Months Past Due	218	117
Three Months or More Past Due, or in Foreclosure	1,715	1,519
Total	$ 342,575	$ 365,954