Fair Value Measurements - Estimated Fair Values of Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Financial Assets:
Cash and due from banks	$ 6,793	$ 6,789
Interest-bearing deposits	10,819	8,900
Federal funds sold	204	120
Securities available-for-sale	36,826	38,522	[1]
Restricted securities	1,980	1,638
Loans, net	256,345	247,912
Loans held for sale	390	196
Accrued interest receivable	1,112	1,124
Mortgage servicing rights	582	579	[1]
Financial Liabilities:
Non-interest-bearing liabilities	58,813	57,805
Savings and other interest-bearing deposits	113,403	114,056
Time deposits	94,870	96,486
Securities sold under repurchase agreements	8,990	9,118
FHLB advances	25,000	15,000
Accrued interest payable	134	167
Fair Value, Inputs, Level 1
Financial Assets:
Cash and due from banks	6,793	6,789
Interest-bearing deposits	10,819	8,900
Federal funds sold	204	120
Financial Liabilities:
Non-interest-bearing liabilities	58,813	57,805
FHLB advances	15,000
Fair Value, Inputs, Level 2
Financial Assets:
Securities available-for-sale	36,826	37,610
Accrued interest receivable	1,112	1,124
Financial Liabilities:
Savings and other interest-bearing deposits	113,403	114,056
Securities sold under repurchase agreements	8,990	9,118
FHLB advances	10,984	15,923
Accrued interest payable	134	167
Fair Value, Inputs, Level 3
Financial Assets:
Securities available-for-sale		912
Restricted securities	1,980	1,638
Loans, net	262,561	253,139
Loans held for sale	390	196
Mortgage servicing rights	582	579
Financial Liabilities:
Time deposits	$ 96,065	$ 98,049

[1] Derived from the audited consolidated financial statements.