Mortgage Servicing Rights and Related Liabilities - Narrative (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022
Servicing Asset at Amortized Cost [Line Items]
Excess spread financing - fair value	$ 459	$ 509
Forward MSRs Sold
Servicing Asset at Amortized Cost [Line Items]
UPB	1,605		$ 20,052
Forward MSRs Sold, Subservicing Retained
Servicing Asset at Amortized Cost [Line Items]
UPB	590		$ 19,367
Excess spread financing
Servicing Asset at Amortized Cost [Line Items]
UPB	$ 78,838	$ 83,706