Commitments and Contingencies - Additional Information (Detail)	3 Months Ended
Mar. 31, 2020 USD ($) shares	Jan. 01, 2020 USD ($)	Dec. 31, 2019 USD ($)
Loss Contingencies [Line Items]
Loan commitments	$ 2,898,000,000		$ 2,779,000,000
Standby letters of credit	82,400,000		87,800,000
Fixed rate loan commitment	2,621,000,000
Floating rate loan commitment	$ 277,000,000.0
Loan commitments floating rate, minimum	0.00%
Loan commitments floating rate, maximum	13.00%
Allowance for unfunded loan commitments	$ 9,000,000.0		2,700,000
Increase in allowance for credit losses on unfunded loan	8,950,000	$ 2,656,000	2,656,000
Extended credit	8,700,000		8,700,000
Credit extensions with collateral	$ 7,700,000		7,700,000
Impact of ASC 326 Adoption
Loss Contingencies [Line Items]
Increase in allowance for credit losses on unfunded loan		$ 4,549,000	$ 4,549,000
Class B Restricted Shares \| Visa
Loss Contingencies [Line Items]
Restricted stock conversion ratio	1.6228
Investment owned, balance, shares \| shares	65,466
Investment owned, at cost	$ 0

Amount of valuation allowance recorded for unfunded commitments to extend credit.

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- Definition

Amount of credit extended with unaffiliated banks related to letter of credit commitments issued on behalf of our clients.

+ References

No definition available.

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- Definition

Amount of collateral provided to secure credit extended with unaffiliated banks related to letter of credit commitments issued on behalf of our clients.

+ References

No definition available.

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Amount of agreement to extend credit in the form of a loan.

+ References

No definition available.

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Maximum floating rate percentage charged on loan commitments.

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Minimum floating rate percentage charged on loan commitments.

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Amount of agreement to extend credit in the form of a standby letter of credit.

+ References

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Restricted stock conversion ratio.

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Cost of the investment.

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Balance held at close of period in number of shares.

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Reflects the amount of cash required to fully fund agreements to provide advances to borrowers and lessees at stated interest rates.

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Reflects the amount of cash required to fully fund agreements to provide advances to borrowers and lessees at interest rates that increase or decrease depending on certain facts or circumstances.

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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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Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

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