Loans - Delinquency Ratio for Consumer Loan (Detail) - USD ($) $ in Millions		Sep. 30, 2024	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Total	[1]	$ 62,014	$ 58,987
Loans carried at lower of amortized cost or fair value of collateral less cost to sell		69	61
Consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current year		3,034	2,726
One year prior to current year		2,523	2,841
Two years prior to current year		2,731	4,125
Three years prior to current year		3,984	2,799
Four years prior to current year		2,672	1,272
Prior		5,765	5,061
Revolving Loans		190	206
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Total		20,899	19,030
Loans in process of foreclosure		33	21
Consumer loans | Residential mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Current year		2,996	2,646
One year prior to current year		2,443	2,764
Two years prior to current year		2,660	4,107
Three years prior to current year		3,965	2,770
Four years prior to current year		2,649	1,244
Prior		5,522	4,810
Revolving Loans		0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Total		20,235	18,341
Consumer loans | Home equity mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Current year		38	80
One year prior to current year		80	69
Two years prior to current year		67	11
Three years prior to current year		9	22
Four years prior to current year		18	25
Prior		181	182
Revolving Loans		0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Total		393	389
Consumer loans | Credit cards
Financing Receivable, Credit Quality Indicator [Line Items]
Current year		0	0
One year prior to current year		0	0
Two years prior to current year		0	0
Three years prior to current year		0	0
Four years prior to current year		0	0
Prior		0	0
Revolving Loans		185	199
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Total		185	199
Consumer loans | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current year		0	0
One year prior to current year		0	8
Two years prior to current year		4	7
Three years prior to current year		10	7
Four years prior to current year		5	3
Prior		62	69
Revolving Loans		5	7
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Total		86	101
Consumer loans | Summary of Two Months and Over Contractual Delinquency
Financing Receivable, Credit Quality Indicator [Line Items]
Current year		0	0
One year prior to current year		1	2
Two years prior to current year		9	6
Three years prior to current year		4	6
Four years prior to current year		10	1
Prior		111	106
Revolving Loans		4	4
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Total		139	125
Consumer loans | Summary of Two Months and Over Contractual Delinquency | Residential mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Current year		0	0
One year prior to current year		1	2
Two years prior to current year		9	6
Three years prior to current year		4	6
Four years prior to current year		9	1
Prior		104	100
Revolving Loans		0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Total		127	115
Consumer loans | Summary of Two Months and Over Contractual Delinquency | Home equity mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Current year		0	0
One year prior to current year		0	0
Two years prior to current year		0	0
Three years prior to current year		0	0
Four years prior to current year		0	0
Prior		5	4
Revolving Loans		0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Total		5	4
Consumer loans | Summary of Two Months and Over Contractual Delinquency | Credit cards
Financing Receivable, Credit Quality Indicator [Line Items]
Current year		0	0
One year prior to current year		0	0
Two years prior to current year		0	0
Three years prior to current year		0	0
Four years prior to current year		0	0
Prior		0	0
Revolving Loans		4	4
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Total		4	4
Consumer loans | Summary of Two Months and Over Contractual Delinquency | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current year		0	0
One year prior to current year		0	0
Two years prior to current year		0	0
Three years prior to current year		0	0
Four years prior to current year		1	0
Prior		2	2
Revolving Loans		0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Total		$ 3	$ 2

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at September 30, 2024 and December 31, 2023. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 15, "Variable Interest Entities," for additional information. September 30, 2024December 31, 2023(in millions)AssetsOther assets$13 $23 Total assets$13 $23 LiabilitiesInterest, taxes and other liabilities$21 $17 Total liabilities$21 $17