Mortgage Loans - Accrued Interest Receivable and Related Charge-Offs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued Interest Receivable	$ 12,254	$ 11,029
Single Family
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued Interest Receivable	10,547	9,776
Financing Receivable, Accrued Interest, Writeoff	(264)	(223)
Multifamily
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued Interest Receivable	663	431
Financing Receivable, Accrued Interest, Writeoff	$ (5)	$ (1)