Loans and Related Allowance for Credit Losses (Home Equity and Residential Real Estate Credit 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
Residential real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		1,488		1,488		5,335
Year two		4,986		4,986		10,064
Year three		9,784		9,784		15,484
Year four		15,070		15,070		6,832
Year five		6,608		6,608		2,270
Prior		9,247		9,247		7,559
Total loans, net		47,183		47,183		47,544
Gross charge-offs
Year two						2
Year three						1
Year four						1
Prior				2		4
Total				2		8
Home equity
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year two
Year three						162
Year four		156		156		1,918
Year five		1,819		1,819		868
Prior		3,155		3,155		2,592
Revolving Loans		8,137		8,137		8,265
Revolving Loans Converted to Term		12,650		12,650		12,345
Total loans, net		25,917		25,917		26,150
Gross charge-offs
Prior				1		4
Revolving Loans				9		7
Revolving Loans Converted to Term				9		10
Total				19		21
Greater than or equal to 780 | Residential real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		813		813		3,206
Year two		3,411		3,411		7,797
Year three		7,691		7,691		12,197
Year four		12,061		12,061		5,035
Year five		4,889		4,889		1,492
Prior		5,190		5,190		4,004
Total loans, net		34,055		34,055		33,731
Greater than or equal to 780 | Home equity
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year two
Year three						102
Year four		100		100		1,254
Year five		1,209		1,209		489
Prior		1,930		1,930		1,605
Revolving Loans		4,597		4,597		4,604
Revolving Loans Converted to Term		6,203		6,203		6,083
Total loans, net		14,039		14,039		14,137
720 to 779 | Residential real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		601		601		1,482
Year two		1,030		1,030		1,659
Year three		1,581		1,581		2,389
Year four		2,160		2,160		1,107
Year five		1,042		1,042		432
Prior		1,684		1,684		1,388
Total loans, net		8,098		8,098		8,457
720 to 779 | Home equity
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year two
Year three						38
Year four		36		36		423
Year five		383		383		216
Prior		643		643		488
Revolving Loans		2,179		2,179		2,222
Revolving Loans Converted to Term		3,243		3,243		3,225
Total loans, net		6,484		6,484		6,612
660 to 719 | Residential real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		71		71		400
Year two		286		286		508
Year three		399		399		657
Year four		594		594		334
Year five		346		346		171
Prior		827		827		721
Total loans, net		2,523		2,523		2,791
660 to 719 | Home equity
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year two
Year three						17
Year four		15		15		174
Year five		166		166		110
Prior		320		320		271
Revolving Loans		1,155		1,155		1,207
Revolving Loans Converted to Term		1,967		1,967		1,894
Total loans, net		3,623		3,623		3,673
Less than 660 | Residential real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		2		2		93
Year two		111		111		71
Year three		84		84		133
Year four		150		150		122
Year five		110		110		82
Prior		733		733		680
Total loans, net		1,190		1,190		1,181
Less than 660 | Home equity
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year two
Year three						5
Year four		5		5		65
Year five		59		59		52
Prior		255		255		220
Revolving Loans		199		199		223
Revolving Loans Converted to Term		1,188		1,188		1,089
Total loans, net		1,706		1,706		1,654
No FICO score available | Residential real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		1		1		140
Year two		134		134		9
Year three		8		8		92
Year four		90		90		168
Year five		157		157		56
Prior		303		303		266
Total loans, net		693		693		731
No FICO score available | Home equity
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year three
Year four						2
Year five		2		2		1
Prior		7		7		8
Revolving Loans		7		7		9
Revolving Loans Converted to Term		49		49		54
Total loans, net		65		65		74
Government insured or guaranteed loans | Residential real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one						14
Year two		14		14		20
Year three		21		21		16
Year four		15		15		66
Year five		64		64		37
Prior		510		510		500
Total loans, net		624		624		653
Greater than 100% | Residential real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		5		5		15
Year two		39		39		139
Year three		133		133		79
Year four		68		68		31
Year five		30		30		10
Prior		33		33		28
Total loans, net		308		308		302
Greater than 100% | Home equity
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year two
Year three						1
Year four		2		2		12
Year five		12		12		6
Prior		17		17		14
Revolving Loans		336		336		306
Revolving Loans Converted to Term		356		356		309
Total loans, net		723		723		648
Greater than or equal to 80% to 100% | Residential real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		507		507		1,665
Year two		838		838		1,928
Year three		1,256		1,256		955
Year four		740		740		221
Year five		199		199		69
Prior		147		147		92
Total loans, net		3,687		3,687		4,930
Greater than or equal to 80% to 100% | Home equity
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year two
Year three						4
Year four		5		5		40
Year five		34		34		17
Prior		32		32		22
Revolving Loans		1,068		1,068		1,116
Revolving Loans Converted to Term		1,631		1,631		1,743
Total loans, net		2,770		2,770		2,942
Less than 80% | Residential real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one		976		976		3,585
Year two		4,054		4,054		7,977
Year three		8,374		8,374		14,421
Year four		14,236		14,236		6,514
Year five		6,315		6,315		2,154
Prior		8,554		8,554		6,935
Total loans, net		42,509		42,509		41,586
Less than 80% | Home equity
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year two
Year three						157
Year four		149		149		1,866
Year five		1,773		1,773		845
Prior		3,106		3,106		2,556
Revolving Loans		6,733		6,733		6,843
Revolving Loans Converted to Term		10,663		10,663		10,293
Total loans, net		22,424		22,424		22,560
No LTV available | Residential real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Year one						56
Year two		41		41
Year three						13
Year four		11		11
Year five
Prior		3		3		4
Total loans, net		$ 55		$ 55		$ 73

[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.