Mortgage Servicing Rights and Related Liabilities - Revenues for Services Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Transfers and Servicing [Abstract]
Contractually specified servicing fees(1)	$ 1,122	$ 1,141
Other service-related income(1)	640	290
Incentive and modification income(1)	51	39
Late fees(1)	71	83
Mark-to-market adjustments(2)	421	(609)
Amortization, net of accretion(3)	(753)	(510)
Other(4)	(279)	(371)
Total revenues - Servicing	1,273	63
Losses for inactive and liquidated loans that are no longer part of the MSR portfolio	35	28
Accretion expense	$ 255	$ 338