Variable Interest Entities - Re-securitizations (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Transfers of securities to VIEs
U.S. GSEs and government agencies	$ 18,864,000,000	$ 16,128,000,000	$ 53,923,000,000
Private label securities transferred to re-securitization VIEs	0	0	$ 0
U.S. GSEs and government agencies | Nonconsolidated re-securitization VIEs
Variable Interest Entity [Line Items]
Interest in VIEs	$ 3,371,000,000	$ 2,580,000,000