Mortgage Loans - TDRs with Sub Defaults (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) contract	Dec. 31, 2020 USD ($) contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings subsequent default | contract		9,243	15,586
Restructured loans, subsequent default | $	$ 2,761	$ 1,510	$ 2,814
Single-family
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings subsequent default | contract		9,243	15,582
Restructured loans, subsequent default | $	2,761	$ 1,510	$ 2,798
Single-family | 20- and 30-year or more, amortizing fixed-rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings subsequent default | contract		7,799	14,127
Restructured loans, subsequent default | $	2,601	$ 1,302	$ 2,578
Single-family | 15-year or less, amortizing fixed-rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings subsequent default | contract		489	148
Restructured loans, subsequent default | $	56	$ 37	$ 10
Single-family | Adjustable-rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings subsequent default | contract		33	16
Restructured loans, subsequent default | $	10	$ 5	$ 2
Single-family | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings subsequent default | contract		922	1,291
Restructured loans, subsequent default | $	94	$ 166	$ 208
Multifamily
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings subsequent default | contract		0	4
Restructured loans, subsequent default | $	$ 0	$ 0	$ 16