Loans and Related Allowance for Credit Losses (Commercial Lending Asset Quality Indicators) (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, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total loans, net	[1]	$ 321,429		$ 321,429		$ 321,508
Gross charge-offs
Total		375	$ 293	705	$ 575
Commercial
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		13,691		13,691		29,806
Year two		25,988		25,988		39,814
Year three		33,454		33,454		12,512
Year four		10,790		10,790		9,535
Year five		8,239		8,239		10,387
Prior		29,691		29,691		23,271
Revolving Loans		98,164		98,164		93,609
Revolving Loans Converted to Term		825		825		624
Total loans, net		220,842		220,842		219,558
Gross charge-offs
Year one				11		29
Year two				24		36
Year three				27		37
Year four				22		24
Year five				6		35
Prior				166		164
Revolving Loans				42		105
Revolving Loans Converted to Term				48		12
Total		198	$ 135	346	$ 255	442
Commercial | Commercial and industrial
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		11,717		11,717		23,857
Year two		19,174		19,174		28,438
Year three		22,290		22,290		8,301
Year four		6,907		6,907		6,114
Year five		5,379		5,379		4,391
Prior		14,824		14,824		12,680
Revolving Loans		97,724		97,724		93,175
Revolving Loans Converted to Term		774		774		624
Total loans, net		178,789		178,789		177,580
Gross charge-offs
Year one				11		25
Year two				14		32
Year three				21		33
Year four				18		8
Year five				3		3
Prior				4		26
Revolving Loans				42		105
Revolving Loans Converted to Term				48		12
Total				161		244
Commercial | Commercial real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		1,204		1,204		4,337
Year two		5,315		5,315		9,871
Year three		9,798		9,798		3,441
Year four		3,220		3,220		2,680
Year five		2,238		2,238		5,509
Prior		13,232		13,232		9,164
Revolving Loans		440		440		434
Revolving Loans Converted to Term		51		51
Total loans, net		35,498		35,498		35,436
Gross charge-offs
Year one
Year two				5
Year three
Year four				2		12
Year five				1		31
Prior				161		137
Revolving Loans
Revolving Loans Converted to Term
Total				169		180
Commercial | Equipment lease financing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		770		770		1,612
Year two		1,499		1,499		1,505
Year three		1,366		1,366		770
Year four		663		663		741
Year five		622		622		487
Prior		1,635		1,635		1,427
Revolving Loans
Revolving Loans Converted to Term
Total loans, net		6,555		6,555		6,542
Gross charge-offs
Year one						4
Year two				5		4
Year three				6		4
Year four				2		4
Year five				2		1
Prior				1		1
Revolving Loans
Revolving Loans Converted to Term
Total				16		18
Pass Rated | Commercial | Commercial and industrial
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		11,419		11,419		23,019
Year two		18,080		18,080		26,657
Year three		19,842		19,842		7,562
Year four		6,104		6,104		5,783
Year five		5,190		5,190		4,110
Prior		14,021		14,021		11,982
Revolving Loans		92,363		92,363		88,467
Revolving Loans Converted to Term		695		695		573
Total loans, net		167,714		167,714		168,153
Pass Rated | Commercial | Commercial real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		1,113		1,113		4,182
Year two		5,125		5,125		8,571
Year three		8,166		8,166		2,986
Year four		2,759		2,759		2,190
Year five		1,761		1,761		4,887
Prior		10,946		10,946		7,411
Revolving Loans		420		420		383
Revolving Loans Converted to Term
Total loans, net		30,290		30,290		30,610
Pass Rated | Commercial | Equipment lease financing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		746		746		1,522
Year two		1,392		1,392		1,424
Year three		1,281		1,281		689
Year four		591		591		690
Year five		580		580		452
Prior		1,590		1,590		1,378
Revolving Loans
Revolving Loans Converted to Term
Total loans, net		6,180		6,180		6,155
Criticized | Commercial | Commercial and industrial
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		298		298		838
Year two		1,094		1,094		1,781
Year three		2,448		2,448		739
Year four		803		803		331
Year five		189		189		281
Prior		803		803		698
Revolving Loans		5,361		5,361		4,708
Revolving Loans Converted to Term		79		79		51
Total loans, net		11,075		11,075		9,427
Criticized | Commercial | Commercial real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		91		91		155
Year two		190		190		1,300
Year three		1,632		1,632		455
Year four		461		461		490
Year five		477		477		622
Prior		2,286		2,286		1,753
Revolving Loans		20		20		51
Revolving Loans Converted to Term		51		51
Total loans, net		5,208		5,208		4,826
Criticized | Commercial | Equipment lease financing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		24		24		90
Year two		107		107		81
Year three		85		85		81
Year four		72		72		51
Year five		42		42		35
Prior		45		45		49
Revolving Loans
Revolving Loans Converted to Term
Total loans, net		$ 375		$ 375		$ 387

[1] Our consolidated assets included the following for which we have elected the fair value option: Loans held for sale of $0.9 billion, Loans held for investment of $1.2 billion and Other assets of $0.1 billion at June 30, 2024. Comparable amounts at December 31, 2023 were $0.7 billion, $1.2 billion and $0.1 billion, respectively.