Loans and Related Allowance for Credit Losses, Allowance for Credit Losses for Loans Activity by Portfolio Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning balance	$ 12,884	$ 16,391	$ 13,788	$ 19,713
Provision for credit losses	773	(1,387)	576	(3,743)
Interest income on certain loans	(26)	(35)	(82)	(112)
Loan charge-offs, total	(736)	(654)	(2,037)	(2,285)
Loan recoveries, total	337	395	989	1,132
Net loan charge-offs	(399)	(259)	(1,048)	(1,153)
Other	(7)	(5)	(9)	0
Allowance for credit losses, ending balance	13,225	14,705	13,225	14,705
Total Commercial [Member]
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning balance	7,082	9,570	7,791	11,516
Provision for credit losses	(72)	(949)	(769)	(2,637)
Interest income on certain loans	(6)	(13)	(22)	(47)
Loan charge-offs, total	(99)	(157)	(235)	(559)
Loan recoveries, total	93	119	235	292
Net loan charge-offs	(6)	(38)	0	(267)
Other	(7)	(5)	(9)	0
Allowance for credit losses, ending balance	6,991	8,565	6,991	8,565
Total Consumer [Member]
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning balance	5,802	6,821	5,997	8,197
Provision for credit losses	845	(438)	1,345	(1,106)
Interest income on certain loans	(20)	(22)	(60)	(65)
Loan charge-offs, loans	(637)	(497)	(1,802)	(1,726)
Loan recoveries, loans	244	276	754	840
Net loan charge-offs	(393)	(221)	(1,048)	(886)
Other	0	0	0	0
Allowance for credit losses, ending balance	$ 6,234	$ 6,140	$ 6,234	$ 6,140