Allowance for Loan Losses - Allowance for Loan Losses by Portfolio Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
ALLOWANCE FOR LOAN LOSSES:
Beginning Balance	$ 3,547	$ 3,439	$ 4,223	$ 3,205
Reclassification of allowance related to sold loans	(27)		(27)
(Charge-offs)	(56)	(161)	(901)	(248)
Recoveries	18	12	39	63
Provision	259	84	407	354
Ending Balance	3,741	3,374	3,741	3,374
Mortgage Loans on Real Estate
ALLOWANCE FOR LOAN LOSSES:
Beginning Balance	2,995	2,889	3,502	2,778
(Charge-offs)	(46)	(12)	(702)	(13)
Recoveries	15	6	25	16
Provision	244	(69)	383	33
Ending Balance	3,208	2,814	3,208	2,814
Commercial and Industrial
ALLOWANCE FOR LOAN LOSSES:
Beginning Balance	435	420	599	323
(Charge-offs)		(132)	(158)	(132)
Recoveries			5
Provision	45	145	34	242
Ending Balance	480	433	480	433
Consumer and Other Loans
ALLOWANCE FOR LOAN LOSSES:
Beginning Balance	117	130	122	104
Reclassification of allowance related to sold loans	(27)		(27)
(Charge-offs)	(10)	(17)	(41)	(103)
Recoveries	3	6	9	47
Provision	(30)	8	(10)	79
Ending Balance	$ 53	$ 127	$ 53	$ 127