Variable Interest Entities - Re-securitizations (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Transfers of securities to VIEs
U.S. GSEs and government agencies	$ 12,772,000,000	$ 6,261,000,000	$ 21,178,000,000	$ 9,667,000,000
Securities Transferred To Private Label Resecuritization VIEs	0	$ 0	0	$ 0
U.S. GSEs and government agencies | Nonconsolidated re-securitization VIEs
Variable Interest Entity [Line Items]
Interest in VIEs	$ 4,879,000,000		$ 4,879,000,000		$ 3,371,000,000