Fair Value of Financial Instruments - Summary of Estimated Fair Values of Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Assets
Cash and due from banks	$ 37,318	$ 31,721
Investment securities, held to maturity	172,449	9,910
Loans held for sale	4,167	3,281
Stock in FHLB and FRB	16,912	14,184
Interest receivable	8,411	7,501
Liabilities
Non-interest bearing deposits	278,527	231,096
Interest payable	477	506
Carrying Amount [Member]
Assets
Cash and due from banks	37,318	31,721
Investment securities, held to maturity	172,449	9,910
Loans held for sale	4,167	3,281
Loans excluding loan level hedges, net	1,224,411	957,464
Stock in FHLB and FRB	16,912	14,184
Interest receivable	8,411	7,501
Liabilities
Non-interest bearing deposits	278,527	231,096
Interest-bearing deposits	1,171,136	1,060,424
Borrowings	350,113	256,296
Subordinated debentures	32,603	32,486
Interest payable	477	506
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets
Cash and due from banks	37,318	31,721
Investment securities, held to maturity
Loans held for sale
Loans excluding loan level hedges, net
Stock in FHLB and FRB
Interest receivable
Liabilities
Non-interest bearing deposits	278,527	231,096
Interest-bearing deposits	0
Borrowings	0
Subordinated debentures	0
Interest payable	0
Significant Other Observable Inputs (Level 2) [Member]
Assets
Cash and due from banks
Investment securities, held to maturity
Loans held for sale
Loans excluding loan level hedges, net
Stock in FHLB and FRB	16,912	14,184
Interest receivable	8,411	7,501
Liabilities
Non-interest bearing deposits
Interest-bearing deposits	1,108,186	1,002,980
Borrowings	351,072	257,093
Subordinated debentures	32,657	32,528
Interest payable	477	506
Significant Unobservable Inputs (Level 3) [Member]
Assets
Cash and due from banks
Investment securities, held to maturity	175,838	9,910
Loans held for sale	4,167	3,281
Loans excluding loan level hedges, net	1,238,805	975,910
Stock in FHLB and FRB
Interest receivable
Liabilities
Non-interest bearing deposits
Interest-bearing deposits
Borrowings
Subordinated debentures
Interest payable

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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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Total amount of interest-bearing domestic deposit liabilities, which may include brokered, retail, demand, checking, notice of withdrawal, money market and other interest-bearing deposits.

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

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Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

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Amount classified as loans attributable to disposal group held for sale or disposed of. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes loans held for sale. Excludes loans and leases covered under loss sharing agreements.

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The aggregate amount of all domestic and foreign noninterest-bearing deposits liabilities held by the entity.

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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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