Fair Value of Financial Instruments - Summary of Estimated Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Assets
Cash and due from banks	$ 72,662	$ 70,832
Investment securities, held to maturity	198,605	193,194
Loans held for sale	3,616	8,087
Loans excluding loan level hedges, net	2,418,656	2,127,894
Stock in FHLB and FRB	15,340	23,932
Interest receivable	14,880	12,713
Liabilities
Non-interest bearing deposits	563,536	496,248
Interest-bearing deposits	2,044,739	1,974,962
Borrowings	458,152	267,489
Subordinated debentures	37,607	37,456
Interest payable	700	472
Carrying Amount [Member]
Assets
Cash and due from banks	72,662	70,832
Investment securities, held to maturity	198,605	193,194
Loans held for sale	3,616	8,087
Loans excluding loan level hedges, net	2,258,023	1,998,804
Stock in FHLB and FRB	15,340	23,932
Interest receivable	14,880	12,713
Liabilities
Non-interest bearing deposits	563,536	496,248
Interest-bearing deposits	2,044,739	1,974,962
Borrowings	458,152	267,489
Subordinated debentures	37,607	37,456
Interest payable	700	472
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets
Cash and due from banks	72,662	70,832
Liabilities
Non-interest bearing deposits	563,536	496,248
Significant Other Observable Inputs (Level 2) [Member]
Assets
Investment securities, held to maturity	202,222	194,086
Stock in FHLB and FRB	15,340	23,932
Interest receivable	14,880	12,713
Liabilities
Interest-bearing deposits	1,948,765	1,839,167
Borrowings	453,303	261,141
Subordinated debentures	36,241	36,371
Interest payable	700	472
Significant Unobservable Inputs (Level 3) [Member]
Assets
Loans held for sale	3,616	8,087
Loans excluding loan level hedges, net	$ 2,205,681	$ 1,965,928

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For banks and other depository institutions: Includes cash on hand (currency and coin), cash items in process of collection, noninterest bearing deposits due from other financial institutions (including corporate credit unions), and noninterest bearing balances with the Federal Reserve Banks, Federal Home Loan Banks and central banks.

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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 Federal Home Loan Bank (FHLB) and Federal Reserve Bank stock.

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Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

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Amount of interest payable on debt, including, but not limited to, trade payables.

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Amount, after allowance for bad debt, of loan receivables held-for-sale that are not part of a disposal group. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.

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