Mortgage Servicing Rights and Related Liabilities - Narrative (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Servicing Asset at Amortized Cost [Line Items]
Excess spread financing - fair value	$ 532	$ 768
Mortgage servicing rights financing - fair value	24	$ 10
Excess Spread Financing Repurchase, Purchase Price	277
Forward MSRs Sold
Servicing Asset at Amortized Cost [Line Items]
UPB	20,052		$ 1,076
Forward MSRs Sold, Subservicing Retained
Servicing Asset at Amortized Cost [Line Items]
UPB	$ 19,367		$ 1,008