Intangible Assets and Other Assets, Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Amortized intangible assets:
Gross carrying value	$ 5,796		$ 5,696
Accumulated amortization	(4,595)		(4,374)
Net carrying value	1,201		1,322
Unamortized intangible assets:
Goodwill	25,174		25,173
Residential mortgage servicing rights [Member]
Unamortized intangible assets:
Mortgage servicing rights, carried at fair value	8,457	$ 8,251	9,310	$ 9,828	$ 9,163	$ 6,920
MSRs [Member]
Amortized intangible assets:
Gross carrying value	5,023		4,942
Accumulated amortization	(3,954)		(3,772)
Net carrying value	1,069		1,170
Customer relationship and other intangibles [Member]
Amortized intangible assets:
Gross carrying value	773		754
Accumulated amortization	(641)		(602)
Net carrying value	$ 132		$ 152