Disclosures about Fair Value of Financial Instruments - Estimated Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets:
Cash and cash equivalents, carrying value	$ 212,505	$ 62,135
Cash and cash equivalents, fair value	212,505	62,135
Debt securities, available for sale	577,198	663,294
Interest-only GNMA securities	16,272
Equity securities	2,406	1,718
Loans held for sale, carrying value	486,328	1,507
Loans held for sale, fair value	486,328	1,507
Loans receivable, net of allowance for loan losses, carrying value	9,508,367	8,503,522
Loans receivable, net of allowance for loan losses, fair value	9,853,037	8,481,128
FHLB, Federal Reserve Bank and other restricted stock, carrying value	84,214	89,685
FHLB, Federal Reserve Bank and other restricted stock, fair value	84,214	89,685
Derivatives	23,608	14,693
Liabilities:
Deposits, carrying value	8,648,936	7,142,236	$ 6,800,142
Deposits, fair value	8,652,340	7,136,009
Federal funds purchased, carrying value	538,000	187,000
Federal funds purchased, fair value	538,000	187,000
FHLB advances, carrying value	850,000	1,248,070
FHLB advances, fair value	852,162	1,248,046
Other borrowings, carrying value	123,630	123,871
Other borrowings, fair value	127,603	121,718
Subordinated debt, carrying value	181,115	108,977
Subordinated debt, fair value	192,217	110,550
Derivatives	45,939	16,286
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash and cash equivalents, fair value	212,505	62,135
Debt securities, available for sale	0	0
Interest-only GNMA securities	0
Equity securities	2,406	1,718
Loans held for sale, fair value	0	0
Loans receivable, net of allowance for loan losses, fair value	0	0
FHLB, Federal Reserve Bank and other restricted stock, fair value	0	0
Derivatives	0	0
Liabilities:
Deposits, fair value	6,980,402	5,408,055
Federal funds purchased, fair value	538,000	187,000
FHLB advances, fair value	0	998,070
Other borrowings, fair value	0	0
Subordinated debt, fair value	0	0
Derivatives	0	0
Significant Other Observable Inputs (Level 2)
Assets:
Cash and cash equivalents, fair value	0	0
Debt securities, available for sale	577,198	663,294
Interest-only GNMA securities	0
Equity securities	0	0
Loans held for sale, fair value	2,130	1,507
Loans receivable, net of allowance for loan losses, fair value	2,245,758	1,405,420
FHLB, Federal Reserve Bank and other restricted stock, fair value	84,214	89,685
Derivatives	23,529	14,624
Liabilities:
Deposits, fair value	1,671,938	1,727,954
Federal funds purchased, fair value	0	0
FHLB advances, fair value	852,162	249,976
Other borrowings, fair value	127,603	121,718
Subordinated debt, fair value	192,217	110,550
Derivatives	45,939	16,286
Significant Unobservable Inputs (Level 3)
Assets:
Cash and cash equivalents, fair value	0	0
Debt securities, available for sale	0	0
Interest-only GNMA securities	16,272
Equity securities	0	0
Loans held for sale, fair value	484,198	0
Loans receivable, net of allowance for loan losses, fair value	7,607,279	7,075,708
FHLB, Federal Reserve Bank and other restricted stock, fair value	0	0
Derivatives	79	69
Liabilities:
Deposits, fair value	0	0
Federal funds purchased, fair value	0	0
FHLB advances, fair value	0	0
Other borrowings, fair value	0	0
Subordinated debt, fair value	0	0
Derivatives	$ 0	$ 0

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Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances, Fair Value Disclosure

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Federal Home Loan Bank Stock And Federal Reserve Bank Stock Fair Value

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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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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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 portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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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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Amount of short term borrowing where a bank borrows, at the federal funds rate, from another bank.

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Fair value portion of short term borrowing where a bank borrows, at the federal funds rate, from another bank.

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Amount of advances from the Federal Home Loan Bank (FHLB).

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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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The carrying amount as of the balance sheet date for the aggregate of other miscellaneous borrowings owed by the reporting entity.

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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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