Goodwill and Mortgage Servicing Rights - Mortgage Fees and Related Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Risk management:
All other	$ 12	$ 1	$ 2
Mortgage fees and related income	3,091	2,036	1,254
Consumer & Community Banking
CCB mortgage fees and related income
Net production revenue	2,629	1,618	268
Operating revenue:
Loan servicing revenue	1,367	1,533	1,835
Changes in MSR asset fair value due to collection/realization of expected cash flows	(899)	(951)	(740)
Total operating revenue	468	582	1,095
Risk management:
Changes in MSR asset fair value due to market interest rates and other	(1,568)	(893)	300
Other changes in MSR asset fair value due to other inputs and assumptions in model	28	(287)	(70)
Change in derivative fair value and other	1,522	1,015	(341)
Total risk management	(18)	(165)	(111)
Total net mortgage servicing revenue	450	417	984
Mortgage fees and related income	$ 3,079	$ 2,035	$ 1,252