Deposits (Additional Information About Corporation's Deposits) (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deposit Liability [Line Items]
Deposits from foreign sources (primarily Mexico)	$ 1,061,701	$ 1,048,943
Non-interest-bearing public funds deposits	14,926,094	17,598,234
Interest-bearing public funds deposits	26,994,474	26,355,962
Total deposits not covered by deposit insurance	22,393,786	23,839,797
Time deposits not covered by deposit insurance	2,339,716	430,128
Deposits from certain directors, executive officers and their affiliates	115,798	153,083
Public Funds [Member]
Deposit Liability [Line Items]
Non-interest-bearing public funds deposits	675,016	788,040
Interest-bearing public funds deposits	$ 630,455	$ 758,761

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
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Amount of uninsured deposit liability.

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The aggregate of all foreign interest-bearing and noninterest-bearing deposit liabilities.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Amount of uninsured time deposit liability in excess of Federal Deposit Insurance Corporation (FDIC) insurance limit or similar state deposit insurance regime in United States of America (US). Excludes time deposit that is otherwise uninsured.

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