Fair Values of off-Balance Sheet Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Assets:
Cash and cash equivalents	$ 65,233	$ 44,618	$ 50,447	$ 39,252
Securities available-for-sale	239,631	254,746
Securities held-to-maturity	7,233	8,193
Other securities	6,249	7,235
Loans, net	740,912	700,539
Bank-owned life insurance	14,771	14,463
Liabilities:
Noninterest-bearing deposits	187,542	201,362
Interest-bearing deposits	776,298	691,413
Subordinated debentures	10,310	10,310
FHLB and other borrowings	58,986	89,450
Quoted Prices (Level 1)
Assets:
Cash and cash equivalents	65,233	44,618
Securities available-for-sale	965	972
Securities held-to-maturity	0	0
Other securities	0	0
Loans, net	0	0
Bank-owned life insurance	0	0
Liabilities:
Noninterest-bearing deposits	0	0
Interest-bearing deposits	0	0
Subordinated debentures	0	0
FHLB and other borrowings	0	0
Significant Other Observable Inputs (Level 2)
Assets:
Cash and cash equivalents	0	0
Securities available-for-sale	236,019	250,973
Securities held-to-maturity	8,651	9,994
Other securities	6,249	7,235
Loans, net	0	0
Bank-owned life insurance	14,771	14,463
Liabilities:
Noninterest-bearing deposits	187,542	201,362
Interest-bearing deposits	775,760	691,036
Subordinated debentures	0	0
FHLB and other borrowings	58,986	89,450
Significant Unobservable Inputs (Level 3)
Assets:
Cash and cash equivalents	0	0
Securities available-for-sale	2,647	2,801
Securities held-to-maturity	0	0
Other securities	0	0
Loans, net	758,614	715,849
Bank-owned life insurance	0	0
Liabilities:
Noninterest-bearing deposits	0	0
Interest-bearing deposits	0	0
Subordinated debentures	10,310	10,310
FHLB and other borrowings	0	0
Estimated Fair Value
Assets:
Cash and cash equivalents	65,233	44,618
Securities available-for-sale	239,631	254,746
Securities held-to-maturity	8,651	9,994
Other securities	6,249	7,235
Loans, net	758,614	715,849
Bank-owned life insurance	14,771	14,463
Liabilities:
Noninterest-bearing deposits	187,542	201,362
Interest-bearing deposits	775,760	691,036
Subordinated debentures	10,310	10,310
FHLB and other borrowings	$ 58,986	$ 89,450

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

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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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The aggregate of all domestic and foreign interest-bearing deposit liabilities.

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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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Other investments not otherwise specified in the taxonomy.

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