Financial Guarantees (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Financial Guarantees and Maximum Recovery [Line Items]
Contractual terms of our guarantees	29 years
Maximum exposure	$ 12,712	$ 14,156
Guaranty obligation	94	101
Maximum recovery	5,070	5,743
Unconsolidated Fannie Mae MBS | Unconsolidated VIEs
Financial Guarantees and Maximum Recovery [Line Items]
Maximum exposure	3,139	3,733
Guaranty obligation	15	16
Maximum recovery	3,058	3,626
Other guaranty arrangements | Unconsolidated VIEs
Financial Guarantees and Maximum Recovery [Line Items]
Maximum exposure	9,573	10,423
Guaranty obligation	79	85
Maximum recovery	2,012	2,117
Agency securities | Unconsolidated VIEs
Financial Guarantees and Maximum Recovery [Line Items]
Freddie Mac collateral included in Fannie Mae commingled security	$ 234,000	$ 212,300