Loans and Related Allowance for Credit Losses (Commercial Quality Indicators) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total loans, net	[1]	$ 321,508	$ 326,025
Gross charge-offs
Total		1,092	985	$ 1,101
Commercial
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		29,806	53,984
Year two		39,814	18,123
Year three		12,512	12,997
Year four		9,535	13,538
Year five		10,387	8,745
Prior		23,271	24,043
Revolving Loans		93,609	93,519
Revolving Loans Converted to Term		624	100
Total loans, net		219,558	225,049
Gross charge-offs
Year One		29
Year Two		36
Year Three		37
Year Four		24
Year Five		35
Prior		164
Revolving Loans		105
Revolving Loans Converted to Term		12
Total		442	307	$ 434
Commercial | Commercial and industrial
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		23,857	42,944
Year two		28,438	12,916
Year three		8,301	8,411
Year four		6,114	6,560
Year five		4,391	4,506
Prior		12,680	13,716
Revolving Loans		93,175	93,066
Revolving Loans Converted to Term		624	100
Total loans, net		177,580	182,219
Gross charge-offs
Year One		25
Year Two		32
Year Three		33
Year Four		8
Year Five		3
Prior		26
Revolving Loans		105
Revolving Loans Converted to Term		12
Total		244
Commercial | Commercial real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		4,337	9,183
Year two		9,871	4,190
Year three		3,441	3,588
Year four		2,680	6,269
Year five		5,509	3,812
Prior		9,164	8,821
Revolving Loans		434	453
Total loans, net		35,436	36,316
Gross charge-offs
Year Four		12
Year Five		31
Prior		137
Total		180
Commercial | Equipment lease financing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		1,612	1,857
Year two		1,505	1,017
Year three		770	998
Year four		741	709
Year five		487	427
Prior		1,427	1,506
Total loans, net		6,542	6,514
Gross charge-offs
Year One		4
Year Two		4
Year Three		4
Year Four		4
Year Five		1
Prior		1
Total		18
Pass Rated | Commercial | Commercial and industrial
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		23,019	41,685
Year two		26,657	12,493
Year three		7,562	8,134
Year four		5,783	6,261
Year five		4,110	4,209
Prior		11,982	13,165
Revolving Loans		88,467	89,384
Revolving Loans Converted to Term		573	69
Total loans, net		168,153	175,400
Pass Rated | Commercial | Commercial real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		4,182	8,835
Year two		8,571	4,153
Year three		2,986	3,266
Year four		2,190	5,511
Year five		4,887	3,005
Prior		7,411	7,454
Revolving Loans		383	450
Total loans, net		30,610	32,674
Pass Rated | Commercial | Equipment lease financing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		1,522	1,797
Year two		1,424	962
Year three		689	942
Year four		690	670
Year five		452	410
Prior		1,378	1,495
Total loans, net		6,155	6,276
Criticized | Commercial | Commercial and industrial
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		838	1,259
Year two		1,781	423
Year three		739	277
Year four		331	299
Year five		281	297
Prior		698	551
Revolving Loans		4,708	3,682
Revolving Loans Converted to Term		51	31
Total loans, net		9,427	6,819
Criticized | Commercial | Commercial real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		155	348
Year two		1,300	37
Year three		455	322
Year four		490	758
Year five		622	807
Prior		1,753	1,367
Revolving Loans		51	3
Total loans, net		4,826	3,642
Criticized | Commercial | Equipment lease financing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		90	60
Year two		81	55
Year three		81	56
Year four		51	39
Year five		35	17
Prior		49	11
Total loans, net		$ 387	$ 238

[1] Our consolidated assets included the following for which we have elected the fair value option: Loans held for sale of $0.7 billion, Loans of $1.2 billion and Other assets of $0.1 billion at December 31, 2023. Comparable amounts at December 31, 2022 were $0.9 billion, $1.3 billion and $0.1 billion, respectively.