Mortgage Servicing Rights and Related Liabilities - Servicing Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Transfers and Servicing [Abstract]
Contractually specified servicing fees(1)	$ 378	$ 275	$ 705	$ 551
Other service-related income(1)	20	214	68	359
Incentive and modification income(1)	9	14	18	28
Late fees(1)	19	16	38	34
Mark-to-market adjustments(2)	200	(140)	753	225
Amortization, net of accretion(3)	(199)	(198)	(401)	(365)
Other(4)	(32)	(76)	(70)	(159)
Total revenues - Servicing	395	105	1,111	673
Cumulative incurred losses related to advances and other receivables associated with inactive and liquidated loans	6	8	12	20
Servicing fee income accretion expense	$ 27	$ 70	$ 60	$ 146