Guarantee Arrangements, Pledged Assets and Repurchase Agreements - Narrative (Detail) - USD ($)		12 Months Ended			36 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2007
Guarantor Obligations [Line Items]
Deferred fees		$ 3,000,000	$ 3,000,000
Carrying value of swap		1,301,082,000,000	1,327,929,000,000
Estimate of reasonably possible loss		100,000,000
Fair Value	[1]	25,696,000,000	27,345,000,000
Trading assets	[1]	22,115,000,000	21,730,000,000
Collateral accepted under security resale agreements, fair value		19,278,000,000	27,913,000,000
Collateral accepted under security repurchase agreements but not reported on the balance sheet that can be sold or repledged, fair value		19,278,000,000	25,838,000,000
Collateral accepted under security repurchase agreements that has been sold or repledged under repurchase agreements or to cover short sales		2,696,000,000	3,290,000,000
Visa Class B Shares
Guarantor Obligations [Line Items]
Loss on Visa shares		40,000,000	36,000,000	$ 3,000,000
Asset Pledged as Collateral with Right
Guarantor Obligations [Line Items]
Fair Value		161,000,000	55,000,000
Trading assets		3,046,000,000	1,255,000,000
Obligation to Repurchase Receivables Sold
Guarantor Obligations [Line Items]
Estimated repurchase liability		23,000,000	15,000,000
Obligation to Repurchase Receivables Sold | Minimum
Guarantor Obligations [Line Items]
Estimate of reasonably possible loss		0
Obligation to Repurchase Receivables Sold | Maximum
Guarantor Obligations [Line Items]
Estimate of reasonably possible loss		30,000,000
HSBC Securities
Guarantor Obligations [Line Items]
Whole loan securitization					$ 24,000,000,000
HSBC Securities | Mortgage Securitization Activity Related Litigation
Guarantor Obligations [Line Items]
Mortgage securitization outstanding loan purchase and sold		2,400,000,000	2,500,000,000
Other liabilities
Guarantor Obligations [Line Items]
Allowance for credit losses on unfunded standby letters of credit		17,000,000	15,000,000
Other liabilities | Standby Letters of Credit
Guarantor Obligations [Line Items]
Deferred fees		49,000,000	52,000,000
Swap
Guarantor Obligations [Line Items]
Carrying value of swap		$ 40,000,000	$ 38,000,000

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at December 31, 2023 and 2022. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 27, "Variable Interest Entities," for additional information. At December 31,20232022(in millions)AssetsLoans, net$— $162 Other assets23 44 Total assets$23 $206 LiabilitiesInterest, taxes and other liabilities$17 $22 Total liabilities$17 $22