Fair Value Measurements - Estimated Fair Values of Company's Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
FINANCIAL ASSETS
Federal funds sold, Carrying Amount	$ 715	$ 1,316
Debt securities held for investment, Carrying Amount	837	1,190
Loans held for investment, net of allowance for credit losses	7,925,613	7,559,845
Debt securities held for investment, Fair Value	837	1,190
Loans held for sale, Fair Value	8,073	3,489
FINANCIAL LIABILITIES
Deposits, Carrying Amount	11,718,546	10,700,122	$ 10,974,228
Short-term borrowings, Carrying Amount		3,351
Subordinated debt, Carrying Amount	86,157	86,101
OFF-BALANCE SHEET FINANCIAL INSTRUMENTS
Loan commitments, Fair Value	4,313	4,875
Letters of credit, Fair Value	769	637
Level 2 Inputs [Member]
FINANCIAL ASSETS
Cash and cash equivalents, Carrying Amount	3,553,772	2,397,463
Federal funds sold, Carrying Amount	715	1,316
Debt securities held for investment, Carrying Amount	2	5
Loans held for sale, Carrying Amount	8,073	3,489
Cash and cash equivalents, Fair Value	3,553,772	2,397,463
Federal funds sold, Fair Value	715	1,316
Debt securities held for investment, Fair Value	2	5
Loans held for sale, Fair Value	8,073	3,489
FINANCIAL LIABILITIES
Deposits, Carrying Amount	11,718,546	10,700,122
Short-term borrowings, Carrying Amount		3,351
Subordinated debt, Carrying Amount	86,157	86,101
Deposits, Fair Value	10,966,958	10,413,348
Short-term borrowings, Fair Value		3,351
Subordinated debt, Fair Value	77,998	79,271
Level 3 Inputs [Member]
FINANCIAL ASSETS
Debt securities held for investment, Carrying Amount	835	1,185
Loans held for investment, net of allowance for credit losses	7,925,613	7,559,845
Debt securities held for investment, Fair Value	835	1,185
Loans held for investment, net of allowance for credit losses, Fair Value	$ 8,643,418	$ 7,356,768

Financial instruments off balance sheet.

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Letters of credit fair value disclosure.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Fair value portion of arrangements with third parties, including, but not limited to, operating lease arrangement and arrangement in which the entity has agreed to expend funds to procure goods or services, or has agreed to commit resources to supply goods or services.

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The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

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Fair value of subordinated debt obligations including, but not limited to, subordinated loan, subordinated bond, subordinated debenture or junior debt.

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The amount outstanding of funds lent to other depository institutions, securities brokers, or securities dealers in the form of Federal Funds sold; for example, immediately available funds lent under agreements or contracts that mature in one business day or roll over under a continuing contract, regardless of the nature of the transaction or the collateral involved, excluding overnight lending for commercial and industrial purposes. Also include Federal Funds sold under agreements to resell on a gross basis, excluding (1) sales of term Federal Funds, (2) due bills representing purchases of securities or other assets by the reporting bank that have not yet been delivered and similar instruments, (3) resale agreements that mature in more than one business day involving assets other than securities, and (4) yield maintenance dollar repurchase agreements.

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Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of subordinated debt (with initial maturities beyond one year or beyond the operating cycle if longer). Subordinated debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets.

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