Loans and Related Allowance for Credit Losses (Rollforward of Allowance for Credit Losses of Loans and Leases) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 4,741	$ 4,868
Charge-offs	(282)	(251)
Recoveries	87	114
Net (charge-offs)	(195)	(137)
Provision for (recapture of) credit losses	229	(172)
Other	1	(1)
Ending balance	4,741	4,558
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	694	662
Provision for (recapture of) credit losses	(22)	(23)
Ending balance	672	639
Allowance for credit loss	5,413	5,197	$ 5,400
Allowances for investment securities and other financial assets	205	158
Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	(35)
Cumulative Effect, Period of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	4,706	4,868
Total commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3,114	3,185
Charge-offs	(120)	(52)
Recoveries	25	34
Net (charge-offs)	(95)	(18)
Provision for (recapture of) credit losses	25	(163)
Other	2	(1)
Ending balance	3,046	3,003
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	613	564
Provision for (recapture of) credit losses	(53)	23
Ending balance	560	587
Allowance for credit loss	3,606	3,590
Total commercial | Cumulative Effect, Period of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3,114	3,185
Total consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,627	1,683
Charge-offs	(162)	(199)
Recoveries	62	80
Net (charge-offs)	(100)	(119)
Provision for (recapture of) credit losses	204	(9)
Other	(1)
Ending balance	1,695	1,555
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	81	98
Provision for (recapture of) credit losses	31	(46)
Ending balance	112	52
Allowance for credit loss	1,807	1,607
Total consumer | Cumulative Effect, Period of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 1,592	$ 1,683