Mortgage Servicing Rights and Related Liabilities - UPB related to owned MSRs (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022
Owned Service Loans [Line Items]
Gain on Sale of Excess Yield	$ 33
Sale of Excess Yield, Total Proceeds	294
Sale of Excess Yield, UPB	41,958
Mortgage servicing rights
Owned Service Loans [Line Items]
UPB	459,476	$ 411,382
Fair Value	7,149	6,654
Forward MSRs Sold
Owned Service Loans [Line Items]
UPB	1,605		$ 20,052
Forward MSRs Sold, Subservicing Retained
Owned Service Loans [Line Items]
UPB	590		$ 19,367
Agency | Mortgage servicing rights
Owned Service Loans [Line Items]
UPB	431,876	380,502
Fair Value	6,848	6,322
Non-agency | Mortgage servicing rights
Owned Service Loans [Line Items]
UPB	27,600	30,880
Fair Value	$ 301	$ 332