Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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As of the balance sheet date of the net amount of unrealized pre-tax gains and losses from hedged loans, that are held for sale, commitments to originate loans for sale and commitments to sell loans, and that meet the criteria of being accounted for as derivative instruments.

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The aggregate fair value of additional assets that would be required to be posted as collateral for derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period.

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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.

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Fair value of securities received as collateral against derivative assets.

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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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Fair value, after offset of derivative asset, of financial liability or 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, elected not to be and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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

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Fair value of securities pledged as collateral against derivative liabilities.

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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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Derivative Financial Instruments - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Notional amounts of derivative contracts entered into for trading account purposes	$ 19,850,000,000	$ 9,400,000,000
Net unrealized pre-tax gains related to hedged loans held for sale, commitments to originate loans for sale and commitments to sell loans	18,000,000	16,000,000
Aggregate fair value of derivative financial instruments in a liability position	21,000,000	13,000,000
Aggregate fair value of derivative financial instruments in asset position	18,000,000	13,000,000
Collateral relating to net asset positions	16,000,000	12,000,000
Counterparties [Member]
Derivative [Line Items]
Post collateral requirements relating to positions	18,000,000	12,000,000
Clearinghouse Credit Facilities [Member]
Derivative [Line Items]
Amount of initial margin posted	65,000,000	52,000,000
Interest Rate Swap Agreements [Member]
Derivative [Line Items]
Increase decrease in net interest income due to interest rate swap agreements	(25,000,000)	25,000,000	$ 37,000,000
Notional amounts of derivative contracts entered into for trading account purposes	19,850,000,000
Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amounts of derivative contracts entered into for trading account purposes	42,900,000,000	29,900,000,000
Foreign Currency and Other Option and Futures Contracts [Member]
Derivative [Line Items]
Notional amounts of derivative contracts entered into for trading account purposes	763,000,000	$ 530,000,000
Credit Risk Derivative [Member]
Derivative [Line Items]
Fair value of additional collateral to be posted for derivative financial instruments	$ 0