Summary of Significant Accounting Policies (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Jun. 30, 2023
Related Parties [Line Items]
Net worth	$ 64,000
Increase in net worth	3,800	$ 1,400
TCCA fees	$ 855		$ 824
Basis points of each dollar of unpaid principal balance	0.042%
Affordable Housing Program obligation	35.00%
Acquired property	$ 1,600	$ 1,600
Weighted average number of contingently issuable shares (shares)	4,700		4,700
Incremental common shares attributable to dilutive effect of conversion of preferred stock (in shares)	26		26
US Treasury
Related Parties [Line Items]
Total available funding from US Treasury pursuant to the senior preferred stock agreement	$ 113,900
Aggregate liquidation preference of senior preferred stock	$ 181,800
Percentage of common shares attributable to warrants	79.90%
Home Affordable Modification Program administrative expense reimbursements	$ 3		$ 4
TCCA, increase of guarantee fee rate	0.10%
TCCA fees	$ 855		824
US Treasury | Other Expense
Related Parties [Line Items]
Affordable Housing Program assessments recognized	11		38
Affordable housing program assessments not remitted	11
US Treasury | Single-Family
Related Parties [Line Items]
Recognized TCCA fees that had not been remitted to Treasury as of period end	855
US Treasury | Forecast
Related Parties [Line Items]
Aggregate liquidation preference of senior preferred stock				$ 185,500
Federal Housing Finance Agency
Related Parties [Line Items]
FHFA assessment fees	39		32
Common Securitization Solutions
Related Parties [Line Items]
Capital contributed	26		$ 22
US Treasury and Government
Related Parties [Line Items]
Aggregate funding received from US Treasury pursuant to the senior preferred stock purchase agreement	$ 119,800