Loans Held for Investment and Allowance for Loan Losses - Additional Information (Detail) - USD ($)	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual, past due 90 days or more and still accruing, restructured loans and foreclosed assets	$ 28,754,000	$ 39,658,000	$ 34,158,000
Additional funds advanced in connection with impaired loans	$ 0
Default for purposes of this disclosure is a troubled debt restructured loan	90 days
Commitments to lend additional funds to borrowers with loan that have been modified as TDRs	$ 0
Loans held by subsidiaries subject to blanket liens	3,560,756,000
Available line of credit	2,063,253,000
Line of credit	0	0	0
Unfunded loan commitments	7,471,000	6,918,000	6,436,000
Total Loans	5,566,169,000	5,322,562,000	$ 5,388,972,000
Provision for Loan and Lease Losses	3,747,000	3,429,000
Federal Home Loan Bank Borrowings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Line of credit	0
Unfunded Loan Commitment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for Loan and Lease Losses	1,035,000	1,432,000
Reversal of Provision for credit losses	$ (4,782,000)	$ 1,997,000

Additional Funds Advanced In Connection With Impaired Construction Loans

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- Definition

Commitment To Lend Additional Funds To Borrowers With Loan Modifications Classified As TDRs

+ References

No definition available.

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- Definition

Carrying amount of loans receivable pledged to secure borrowing lines with the Federal Home Loan Bank of Dallas.

+ References

No definition available.

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- Definition

Loans still accruing past due ninety days or more restructured loans foreclosed assets.

+ References

No definition available.

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- Definition

Period of loans in default treated as troubled debt restructuring.

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No definition available.

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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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No definition available.

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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- Definition

The maximum amount of borrowing capacity under a line of credit that is available as of the balance sheet date for financing purchases of goods acquired for inventory or imminent delivery to a customer.

+ References

No definition available.

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- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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- Definition

Amount of undisbursed portion of the loan receivable balance (loans in process). Excludes loans and leases covered under loss sharing agreements.

+ References

No definition available.

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- Definition

Amount of expense related to estimated loss from loan and lease transactions.

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- Definition

Amount of credit loss expense (reversal of expense) for financing receivable.

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