Allowance for Loan Losses - Allowance for Loan Losses by Portfolio Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
ALLOWANCE FOR LOAN LOSSES:
Beginning Balance	$ 3,439	$ 2,973	$ 3,205	$ 2,925
(Charge-offs)	(161)	(32)	(248)	(267)
Recoveries	12	20	63	41
Provision	84	190	354	452
Ending Balance	3,374	3,151	3,374	3,151
Mortgage Loans on Real Estate
ALLOWANCE FOR LOAN LOSSES:
Beginning Balance	2,889	2,589	2,778	2,465
(Charge-offs)	(12)	(10)	(13)	(224)
Recoveries	6	15	16	29
Provision	(69)	109	33	433
Ending Balance	2,814	2,703	2,814	2,703
Commercial and Industrial
ALLOWANCE FOR LOAN LOSSES:
Beginning Balance	420	211	323	256
(Charge-offs)	(132)		(132)
Provision	145	91	242	46
Ending Balance	433	302	433	302
Consumer and Other Loans
ALLOWANCE FOR LOAN LOSSES:
Beginning Balance	130	173	104	204
(Charge-offs)	(17)	(22)	(103)	(43)
Recoveries	6	5	47	12
Provision	8	(10)	79	(27)
Ending Balance	$ 127	$ 146	$ 127	$ 146