Consolidations and Transfers of Financial Assets - Transfers of Financial Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Transfers of Financial Assets [Line Items]
Portfolio securitizations: unpaid principal balance	$ 28,300	$ 102,800
Unconsolidated VIEs
Transfers of Financial Assets [Line Items]
Retained interests: principal and interest received	78	$ 114
Unconsolidated VIEs | Single Class MBS, REMIC & Megas
Transfers of Financial Assets [Line Items]
Retained interests: unpaid principal balance	875		$ 910
Retained interests: fair value	$ 1,400		$ 1,400