Fair Value of Financial Instruments - Schedule of Estimated Fair Value and Related Carrying or Notional Amounts of Company's Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Assets:
Cash and cash equivalents	$ 25,053	$ 34,166	$ 41,443	$ 47,720
Investment securities available-for-sale	202,247	204,966
Investment securities held-to-maturity	43,929	29,120
Federal Home Loan Bank stock	740	738
Loans, net of allowance for loan losses	244,993	259,516	$ 272,086
Other assets – derivatives	9,527	10,394
Held-to-Maturity, Estimated Fair Value	43,629	29,154
Liabilities:
Deposits	471,141	483,659
Short-term borrowings	985	436
Long-term debt	5,000	5,000
Level 1 [Member]
Assets:
Cash and cash equivalents	25,053	34,166
Level 2 [Member]
Assets:
Investment securities available-for-sale	202,247	204,966
Held-to-Maturity, Estimated Fair Value	43,629	29,154
Other assets – derivatives	14	68
Liabilities:
Deposits	471,692	484,108
Short-term borrowings	985	436
Long-term debt	5,002	5,007
Level 3 [Member]
Assets:
Federal Home Loan Bank stock	740	738
Loans, net of allowance for loan losses	246,865	259,337
Carrying Amount [Member]
Assets:
Cash and cash equivalents	25,053	34,166
Investment securities available-for-sale	202,247	204,966
Investment securities held-to-maturity	43,929	29,120
Federal Home Loan Bank stock	740	738
Loans, net of allowance for loan losses	244,993	259,516
Other assets – derivatives	14	68
Liabilities:
Deposits	471,141	483,659
Short-term borrowings	985	436
Long-term debt	5,000	5,000
Estimated Fair Value [Member]
Assets:
Investment securities available-for-sale	202,247	204,966
Cash and cash equivalents	25,053	34,166
Held-to-Maturity, Estimated Fair Value	43,629	29,154
Federal Home Loan Bank stock	740	738
Loans, net of allowance for loan losses	246,865	259,337
Other assets – derivatives	14	68
Liabilities:
Deposits	471,692	484,108
Short-term borrowings	985	436
Long-term debt	$ 5,002	$ 5,007