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v3.23.2

Loans - Additional Information (Detail) $ in Thousands | 3 Months Ended | 6 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Jun. 30, 2023 USD ($) | Jun. 30, 2022 USD ($) | Jun. 30, 2023 USD ($) | Jun. 30, 2022 USD ($) | Mar. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Mar. 31, 2022 USD ($) | Dec. 31, 2021 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Concentration of loans in a single industry in excess of ten percent | 0.00% |  | 0.00% |  |  |  |  |
Maximum percentage loan related to single industry | 10.00% |  | 10.00% |  |  |  |  |
U.S. dollar denominated loans and commitments to borrowers in Mexico | $ 0 |  | $ 0 |  |  | $ 0 |  |
Loans and Leases Receivable, Related Parties | $ 389,200 |  | $ 389,200 |  |  | $ 391,300 |  |
Texas Leading Index economic condition indicator | 127.7 |  | 127.7 |  |  | 130.3 |  |
Financing Receivable, Change in Method, Credit Loss Expense (Reversal) |  |  | $ (45,000) |  |  |  |  |
Financing Receivable, Allowance for Credit Loss | $ 233,619 |  | 233,619 |  |  | $ 227,621 |  |
Loans, net of unearned discounts | 17,746,311 |  | 17,746,311 |  |  | 17,154,969 |  |
Nonperforming Financial Instruments [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Year One, Originated, Current Fiscal Year | 12,248 |  | 12,248 |  |  |  |  |
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year | 8 |  | 8 |  |  |  |  |
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Nonperforming Financial Instruments [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Year One, Originated, Current Fiscal Year | 8,267 |  | 8,267 |  |  |  |  |
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year | 4,562 |  | 4,562 |  |  |  |  |
Payment Deferral |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Loans, net of unearned discounts | 0 | $ 1,116 | 0 | $ 1,116 |  |  |  |
Additional Funding Agreement Terms |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Loans, net of unearned discounts | $ 0 |  | $ 0 |  |  |  |  |
Commercial and Industrial Total Energy Loans [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Percentage of total energy loans to total loans | 5.60% |  | 5.60% |  |  |  |  |
Financing Receivable, Allowance for Credit Loss | $ 14,929 | 16,267 | $ 14,929 | 16,267 | $ 19,191 | 18,062 | $ 15,422 | $ 17,217
Financing Receivable, Allowance for Credit Loss, Writeoff | 518 | 0 | 518 | 371 |  |  |  |
Loans, net of unearned discounts | 986,571 |  | 986,571 |  |  | 925,729 |  |
Financing Receivable, Year One, Originated, Current Fiscal Year | 311,743 |  | 311,743 |  |  |  |  |
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year | 70,287 |  | 70,287 |  |  |  |  |
Commercial and Industrial Total Energy Loans [Member] | Nonperforming Financial Instruments [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Year One, Originated, Current Fiscal Year | 10,324 |  | 10,324 |  |  |  |  |
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year | 0 |  | 0 |  |  |  |  |
Commercial and Industrial Total Energy Loans [Member] | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Nonperforming Financial Instruments [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Year One, Originated, Current Fiscal Year | 0 |  | 0 |  |  |  |  |
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year | 0 |  | 0 |  |  |  |  |
Paycheck Protection Program [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Allowance for Credit Loss | 0 | 0 | 0 | 0 |  | 0 |  |
Loans, net of unearned discounts | 22,333 |  | 22,333 |  |  | 34,852 |  |
Non Accrual Loans [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Additional interest that would have been recognized on non-accrual loans, net of tax | 835 | 436 | 1,400 | 843 |  |  |  |
Total consumer real estate loans [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Allowance for Credit Loss | 13,035 | 6,854 | 13,035 | 6,854 | 9,708 | 8,004 | 6,359 | 6,585
Financing Receivable, Allowance for Credit Loss, Writeoff | 1,080 | 131 | 1,330 | 362 |  |  |  |
Loans, net of unearned discounts | 2,157,916 |  | 2,157,916 |  |  | 1,843,539 |  |
Total consumer real estate loans [Member] | Nonperforming Financial Instruments [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Year One, Originated, Current Fiscal Year | 0 |  | 0 |  |  |  |  |
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year | 0 |  | 0 |  |  |  |  |
Total consumer real estate loans [Member] | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Nonperforming Financial Instruments [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Year One, Originated, Current Fiscal Year | 0 |  | 0 |  |  |  |  |
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year | 0 |  | 0 |  |  |  |  |
Commercial Portfolio Segment [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Allowance for Credit Loss | 75,166 | 87,270 | 75,166 | 87,270 | 78,465 | 104,237 | 87,026 | 72,091
Financing Receivable, Allowance for Credit Loss, Writeoff | 7,136 | 1,891 | 13,316 | 5,346 |  |  |  |
Loans, net of unearned discounts | 5,726,804 |  | 5,726,804 |  |  | 5,674,798 |  |
Financing Receivable, Year One, Originated, Current Fiscal Year | 1,145,305 |  | 1,145,305 |  |  |  |  |
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year | 941,744 |  | 941,744 |  |  |  |  |
Commercial Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Year One, Originated, Current Fiscal Year | 0 |  | 0 |  |  |  |  |
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year | 0 |  | 0 |  |  |  |  |
Commercial Portfolio Segment [Member] | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Nonperforming Financial Instruments [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Year One, Originated, Current Fiscal Year | 124 |  | 124 |  |  |  |  |
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year | 208 |  | 208 |  |  |  |  |
Commercial Portfolio Segment [Member] | Payment Deferral |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Loans, net of unearned discounts | 0 |  | 0 |  |  |  |  |
Consumer Loan [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Allowance for Credit Loss | 9,563 | 12,135 | 9,563 | 12,135 | $ 8,457 | 7,017 | $ 9,074 | $ 7,837
Financing Receivable, Allowance for Credit Loss, Writeoff | 7,016 | $ 5,322 | 13,958 | $ 11,093 |  |  |  |
Loans, net of unearned discounts | 459,720 |  | 459,720 |  |  | 492,726 |  |
Consumer Loan [Member] | Nonperforming Financial Instruments [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Year One, Originated, Current Fiscal Year | 0 |  | 0 |  |  |  |  |
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year | 0 |  | 0 |  |  |  |  |
Consumer Loan [Member] | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Nonperforming Financial Instruments [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Year One, Originated, Current Fiscal Year | 8,143 |  | 8,143 |  |  |  |  |
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year | 4,354 |  | 4,354 |  |  |  |  |
Bank Overdrafts | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Nonperforming Financial Instruments [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Year One, Originated, Current Fiscal Year | 8,100 |  | 8,100 |  |  |  |  |
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year | 4,200 |  | 4,200 |  |  |  |  |
Commitments to Extend Credit [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financial instruments with off- balance-sheet risk | 12,208,032 |  | 12,208,032 |  |  | 12,137,957 |  |
Commitments to Extend Credit [Member] | Automobile Loan |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Unfunded balances | 454,900 |  | 454,900 |  |  |  |  |
Commitments to Extend Credit [Member] | Commercial and Industrial Total Energy Loans [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Unfunded balances | 1,000,000 |  | 1,000,000 |  |  |  |  |
Standby Letters of Credit [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financial instruments with off- balance-sheet risk | 405,900 |  | 405,900 |  |  | 383,851 |  |
Standby Letters of Credit [Member] | Commercial and Industrial Total Energy Loans [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Unfunded balances | 84,100 |  | 84,100 |  |  |  |  |
Standby Letters of Credit [Member] | Automobiles |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Unfunded balances | 20,100 |  | 20,100 |  |  |  |  |
Loans Receivable [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Interest Receivable | $ 73,900 |  | $ 73,900 |  |  | $ 68,700 |  |

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