Loans and Related Allowance for Credit Losses (Rollforward of Allowance for Credit Losses of Loans and Leases) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 4,737	$ 4,462	$ 4,741	$ 4,868
Charge-offs	(233)	(222)	(808)	(668)
Recoveries	112	103	298	329
Net (charge-offs)	(121)	(119)	(510)	(339)
Provision for (recapture of) credit losses	153	241	571	59
Other	(2)	(3)		(7)
Ending balance	4,767	4,581	4,767	4,581
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	663	681	694	662
Provision for (recapture of) credit losses	(23)	1	(54)	20
Ending balance	640	682	640	682
Allowance for credit loss	5,407	5,263	5,407	5,263	$ 5,400
Allowances for investment securities and other financial assets	131	162	131	162
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	4,737	4,462	4,706	4,868
Total commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3,142	2,937	3,114	3,185
Charge-offs	(72)	(73)	(327)	(162)
Recoveries	49	25	110	78
Net (charge-offs)	(23)	(48)	(217)	(84)
Provision for (recapture of) credit losses	105	174	325	(34)
Other	(2)	(2)		(6)
Ending balance	3,222	3,061	3,222	3,061
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	555	630	613	564
Provision for (recapture of) credit losses	(22)	(22)	(80)	44
Ending balance	533	608	533	608
Allowance for credit loss	3,755	3,669	3,755	3,669
Total commercial | Cumulative Effect, Period of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3,142	2,937	3,114	3,185
Total consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,595	1,525	1,627	1,683
Charge-offs	(161)	(149)	(481)	(506)
Recoveries	63	78	188	251
Net (charge-offs)	(98)	(71)	(293)	(255)
Provision for (recapture of) credit losses	48	67	246	93
Other		(1)		(1)
Ending balance	1,545	1,520	1,545	1,520
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	108	51	81	98
Provision for (recapture of) credit losses	(1)	23	26	(24)
Ending balance	107	74	107	74
Allowance for credit loss	1,652	1,594	1,652	1,594
Total consumer | Cumulative Effect, Period of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 1,595	$ 1,525	$ 1,592	$ 1,683