Mortgage Loans - Loan Restructuring - Aging Analysis (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	$ 57,198
Serious delinquency: days past due	90 days
Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	$ 51,895
30 - 59 Days Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	4,391
60 - 89 Days Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	2,980
Seriously Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	15,256
Total Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	22,627
Current | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	29,268
Single-family
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	$ 56,875
Single-family | Minimum
Loans in Mortgage Portfolio [Line Items]
Serious delinquency: days past due	90 days	90 days
Single-family | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	$ 51,572
Single-family | 30 - 59 Days Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	4,388
Single-family | 60 - 89 Days Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	2,980
Single-family | Seriously Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	14,991
Single-family | Total Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	22,359
Single-family | Current | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	29,213
Single-family | 20- and 30-year or more, amortizing fixed-rate
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	53,310
Single-family | 20- and 30-year or more, amortizing fixed-rate | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	48,272
Single-family | 20- and 30-year or more, amortizing fixed-rate | 30 - 59 Days Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	4,113
Single-family | 20- and 30-year or more, amortizing fixed-rate | 60 - 89 Days Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	2,785
Single-family | 20- and 30-year or more, amortizing fixed-rate | Seriously Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	13,995
Single-family | 20- and 30-year or more, amortizing fixed-rate | Total Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	20,893
Single-family | 20- and 30-year or more, amortizing fixed-rate | Current | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	27,379
Single-family | 15-year or less, amortizing fixed-rate
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	1,907
Single-family | 15-year or less, amortizing fixed-rate | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	1,775
Single-family | 15-year or less, amortizing fixed-rate | 30 - 59 Days Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	147
Single-family | 15-year or less, amortizing fixed-rate | 60 - 89 Days Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	114
Single-family | 15-year or less, amortizing fixed-rate | Seriously Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	552
Single-family | 15-year or less, amortizing fixed-rate | Total Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	813
Single-family | 15-year or less, amortizing fixed-rate | Current | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	962
Single-family | Adjustable-rate
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	241
Single-family | Adjustable-rate | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	225
Single-family | Adjustable-rate | 30 - 59 Days Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	15
Single-family | Adjustable-rate | 60 - 89 Days Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	14
Single-family | Adjustable-rate | Seriously Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	79
Single-family | Adjustable-rate | Total Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	108
Single-family | Adjustable-rate | Current | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	117
Single-family | Other
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	1,417
Single-family | Other | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	1,300
Single-family | Other | 30 - 59 Days Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	113
Single-family | Other | 60 - 89 Days Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	67
Single-family | Other | Seriously Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	365
Single-family | Other | Total Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	545
Single-family | Other | Current | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	755
Multifamily
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	$ 323
Multifamily | Minimum
Loans in Mortgage Portfolio [Line Items]
Serious delinquency: days past due	60 days
Multifamily | Maximum
Loans in Mortgage Portfolio [Line Items]
Serious delinquency: days past due	89 days
Multifamily | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	$ 323
Multifamily | 30 - 59 Days Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	3
Multifamily | Seriously Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	265
Multifamily | Total Delinquent | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	268
Multifamily | Current | Forbearance and Repayment Plans and Trial Modification
Loans in Mortgage Portfolio [Line Items]
Restructured loans, amortized cost	$ 55