Loans and Related Allowance for Credit Losses (Rollforward of Allowance for Credit Losses of Loans and Leases) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 4,693	$ 4,741	$ 4,791	$ 4,741	$ 4,741
Charge-offs	(375)	(293)	(705)	(575)
Recoveries	113	99	200	186
Net (charge-offs)	(262)	(194)	(505)	(389)
Provision for (recapture of) credit losses	204	189	351	418
Other	1	1	(1)	2
Ending balance	4,636	4,737	4,636	4,737	4,791
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	672	672	663	694	694
Provision for (recapture of) credit losses	45	(9)	54	(31)
Ending balance	717	663	717	663	663
Allowance for credit loss	5,353	5,400	5,353	5,400	5,500
Allowances for investment securities and other financial assets	112	171	112	171
Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance				(35)	(35)
Cumulative Effect, Period of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	4,693	4,741	4,791	4,706	4,706
Ending balance					4,791
Total commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3,217	3,046	3,259	3,114	3,114
Charge-offs	(198)	(135)	(346)	(255)	(442)
Recoveries	52	36	75	61
Net (charge-offs)	(146)	(99)	(271)	(194)
Provision for (recapture of) credit losses	172	195	257	220
Other			(2)	2
Ending balance	3,243	3,142	3,243	3,142	3,259
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	528	560	545	613	613
Provision for (recapture of) credit losses	53	(5)	36	(58)
Ending balance	581	555	581	555	545
Allowance for credit loss	3,824	3,697	3,824	3,697
Total commercial | Cumulative Effect, Period of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3,217	3,046	3,259	3,114	3,114
Ending balance					3,259
Total consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,476	1,695	1,532	1,627	1,627
Charge-offs	(177)	(158)	(359)	(320)
Recoveries	61	63	125	125
Net (charge-offs)	(116)	(95)	(234)	(195)
Provision for (recapture of) credit losses	32	(6)	94	198
Other	1	1	1
Ending balance	1,393	1,595	1,393	1,595	1,532
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	144	112	118	81	81
Provision for (recapture of) credit losses	(8)	(4)	18	27
Ending balance	136	108	136	108	118
Allowance for credit loss	1,529	1,703	1,529	1,703
Total consumer | Cumulative Effect, Period of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 1,476	$ 1,695	$ 1,532	$ 1,592	1,592
Ending balance					$ 1,532