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, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 4,462	$ 5,730	$ 4,868	$ 5,361
Acquisition PCD reserves		(59)		1,056
Charge-offs	(222)	(206)	(668)	(877)
Recoveries	103	125	329	344
Net (charge-offs)	(119)	(81)	(339)	(533)
Provision for (recapture of) credit losses	241	(229)	59	(525)
Other	(3)	(6)	(7)	(4)
Ending balance	4,581	5,355	4,581	5,355
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	681	645	662	584
Acquisition PCD reserves				46
Provision for (recapture of) credit losses	1	1	20	16
Ending balance	682	646	682	646
Allowance for credit loss	5,263	6,001	5,263	6,001
Allowances for investment securities and other financial assets	162	162	162	162
Total commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	2,937	3,812	3,185	3,337
Acquisition PCD reserves		(54)		774
Charge-offs	(73)	(50)	(162)	(393)
Recoveries	25	29	78	81
Net (charge-offs)	(48)	(21)	(84)	(312)
Provision for (recapture of) credit losses	174	(129)	(34)	(193)
Other	(2)	(5)	(6)	(3)
Ending balance	3,061	3,603	3,061	3,603
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	630	533	564	485
Acquisition PCD reserves				43
Provision for (recapture of) credit losses	(22)	2	44	7
Ending balance	608	535	608	535
Allowance for credit loss	3,669	4,138	3,669	4,138
Total consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,525	1,918	1,683	2,024
Acquisition PCD reserves		(5)		282
Charge-offs	(149)	(156)	(506)	(484)
Recoveries	78	96	251	263
Net (charge-offs)	(71)	(60)	(255)	(221)
Provision for (recapture of) credit losses	67	(100)	93	(332)
Other	(1)	(1)	(1)	(1)
Ending balance	1,520	1,752	1,520	1,752
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	51	112	98	99
Acquisition PCD reserves				3
Provision for (recapture of) credit losses	23	(1)	(24)	9
Ending balance	74	111	74	111
Allowance for credit loss	$ 1,594	$ 1,863	$ 1,594	$ 1,863