Loans - Schedule of Aging of Past Due and Nonaccrual Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 430,322	$ 419,645
Non-Accrual	1,687	1,576
Total Past Due and Non-Accrual	2,663	2,768
Total ending loans balance	432,985	422,413
30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	341	683
60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	407	404
90 Days Plus Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	228	105
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	128,225	122,760
Non-Accrual	444	177
Total Past Due and Non-Accrual	699	383
Total ending loans balance	128,924	123,143
Commercial [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	86	34
Commercial [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	169	172
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	152,192	147,920
Non-Accrual	669	796
Total Past Due and Non-Accrual	816	855
Total ending loans balance	153,008	148,775
Commercial Real Estate [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	108	59
Commercial Real Estate [Member] | 90 Days Plus Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	39
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	126,063	124,408
Non-Accrual	574	603
Total Past Due and Non-Accrual	1,036	1,367
Total ending loans balance	127,099	125,775
Residential Real Estate [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	180	486
Residential Real Estate [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	93	173
Residential Real Estate [Member] | 90 Days Plus Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	189	105
Construction & Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	13,558	15,452
Total Past Due and Non-Accrual	13
Total ending loans balance	13,571	15,452
Construction & Land Development [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	13
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	10,284	9,105
Total Past Due and Non-Accrual	99	163
Total ending loans balance	10,383	9,268
Consumer [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	62	$ 163
Consumer [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 37