Fair Value Measurements - Estimated Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Financial Assets:
Cash and due from banks	$ 4,969	$ 6,181
Interest-bearing deposits	15,330	14,784
Federal funds sold	271	119
Securities available-for-sale	59,825	42,604
Restricted securities	2,731	2,430
Loans, net	343,323	295,242
Loans held for sale	270
Accrued interest receivable	1,318	1,197
Mortgage servicing rights	658	596
Financial Liabilities:
Non-interest-bearing liabilities	65,842	63,308
Savings and other interest-bearing deposits	166,628	122,502
Time deposits	127,388	121,775
Securities sold under repurchase agreements	7,161	6,012
FHLB advances	40,000	35,000
Subordinated debt	6,844
Accrued interest payable	318	149
Financial Assets:
Cash and due from banks	4,969	6,181
Interest-bearing deposits	15,330	14,784
Federal funds sold	271	119
Securities available-for-sale	59,825	42,604
Restricted securities	2,731	2,430
Loans, net	347,500	300,481
Loans held for sale	270
Accrued interest receivable	1,318	1,197
Mortgage servicing rights	658	596
Financial Liabilities:
Non-interest-bearing liabilities	65,842	63,308
Savings and other interest-bearing deposits	166,628	122,502
Time deposits	127,433	122,662
Securities sold under repurchase agreements	7,161	6,012
FHLB advances	40,855	35,951
Subordinated debt	7,000
Accrued interest payable	318	149
Fair Value, Inputs, Level 1
Financial Assets:
Securities available-for-sale	1,216	845
Financial Assets:
Cash and due from banks	4,969	6,181
Interest-bearing deposits	15,330	14,784
Federal funds sold	271	119
Securities available-for-sale	1,216	845
Financial Liabilities:
Non-interest-bearing liabilities	65,842	63,308
Fair Value, Inputs, Level 2
Financial Assets:
Securities available-for-sale	54,416	41,759
Financial Assets:
Securities available-for-sale	54,416	41,759
Accrued interest receivable	1,318	1,197
Financial Liabilities:
Savings and other interest-bearing deposits	166,628	122,502
Securities sold under repurchase agreements	7,161	6,012
FHLB advances	40,855	35,951
Accrued interest payable	318	149
Fair Value, Inputs, Level 3
Financial Assets:
Securities available-for-sale	4,193
Financial Assets:
Securities available-for-sale	4,193
Restricted securities	2,731	2,430
Loans, net	347,500	300,481
Loans held for sale	270
Mortgage servicing rights	658	596
Financial Liabilities:
Time deposits	127,433	$ 122,662
Subordinated debt	$ 7,000