Changes in cash flow hedges derivative instruments at fair value net.

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- Definition

The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
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- Definition

Fair value of securities received as collateral against derivative assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
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-Name Accounting Standards Codification
-Section 55
-Paragraph 12
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- Definition

Fair value, after offset of derivative liability, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, before offset against an obligation to return collateral under a master netting arrangement. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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- Definition

Indicates line item in statement of income or comprehensive income that includes gain (loss) from effective portion of derivative instrument reclassified from accumulated other comprehensive income (AOCI) into income.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
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- Definition

Amount of unrealized gain (loss) related to the increase or decrease in fair value of interest rate derivatives designated as cash flow hedging instruments, which was recorded in accumulated other comprehensive income to the extent that the cash flow hedge was determined to be effective.

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Derivative Financial Instruments - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Derivative [Line Items]
Notional amounts of derivative contracts entered into for trading account purposes	$ 27,277		$ 26,977
Unrealized net loss recognized in other comprehensive income related to cash flow hedges	359
Aggregate fair value of derivative financial instruments in asset position	232		179
Collateral relating to net asset positions	231		179
Clearinghouse Credit Facilities [Member]
Derivative [Line Items]
Amount of initial margin posted	146		129
Interest Income [Member]
Derivative [Line Items]
Changes in Cash Flow Hedges Derivative Instruments At Fair Value Net	87	$ 59
Interest Rate Swap Agreements [Member]
Derivative [Line Items]
Increase decrease in net interest income due to interest rate swap agreements	$ 100	$ 69
Derivative Instrument, Gain (Loss) Reclassified from AOCI into Income, Effective Portion, Statement of Income or Comprehensive Income [Extensible Enumeration]	Interest and Dividend Income, Operating	Interest and Dividend Income, Operating
Interest Rate Swap Agreements [Member] \| Maturity Period 2024 [Member]
Derivative [Line Items]
Unrealized net loss recognized in other comprehensive income related to cash flow hedges	$ 1
Interest Rate Swap Agreements [Member] \| Maturity Period 2025 [Member]
Derivative [Line Items]
Unrealized net loss recognized in other comprehensive income related to cash flow hedges	227
Interest Rate Swap Agreements [Member] \| Maturity Period 2026 [Member]
Derivative [Line Items]
Unrealized net loss recognized in other comprehensive income related to cash flow hedges	129
Interest Rate Swap Agreements [Member] \| Maturity Period 2027 [Member]
Derivative [Line Items]
Unrealized net loss recognized in other comprehensive income related to cash flow hedges	2
Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amounts of derivative contracts entered into for trading account purposes	43,400		44,400
Foreign Exchange and Other Option and Futures Contracts [Member]
Derivative [Line Items]
Notional amounts of derivative contracts entered into for trading account purposes	$ 1,700		$ 1,500