Loan Portfolio Aging Analysis (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non Accrual	$ 1,549	$ 958
Total Past Due and Non Accrual	3,406	1,869
Current	322,919	313,885
Total Loans Receivable	326,325	315,754
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non Accrual	1,577	756
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non Accrual	149	28
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non Accrual	131	127
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non Accrual	29	46
Total Past Due and Non Accrual	229	46
Current	61,492	52,240
Total Loans Receivable	61,721	52,286
Commercial | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non Accrual	200	0
Commercial | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non Accrual	0	0
Commercial | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non Accrual	0	0
Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non Accrual	404	247
Total Past Due and Non Accrual	712	768
Current	162,510	157,546
Total Loans Receivable	163,222	158,314
Commercial Real Estate | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non Accrual	137	394
Commercial Real Estate | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non Accrual	40	0
Commercial Real Estate | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non Accrual	131	127
Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non Accrual	869	658
Total Past Due and Non Accrual	2,016	967
Current	81,184	82,903
Total Loans Receivable	83,200	83,870
Residential | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non Accrual	1,068	292
Residential | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non Accrual	79	17
Residential | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non Accrual	0	0
Installment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non Accrual	247	7
Total Past Due and Non Accrual	449	88
Current	17,733	21,196
Total Loans Receivable	18,182	21,284
Installment | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non Accrual	172	70
Installment | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non Accrual	30	11
Installment | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non Accrual	$ 0	$ 0