Loans - Recorded Investment in Past Due and Non-accruing Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due	$ 2,767	$ 1,502
90 Days or More Past Due and Still Accruing	395	14
Nonaccruals	4,447	1,954
Total Past Due and Nonaccruals	7,609	3,470
Current	308,932	294,584
Total Gross Loans	316,541	298,054
Construction, Land and Land Development
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due	47	64
90 Days or More Past Due and Still Accruing	67
Nonaccruals	768	669
Total Past Due and Nonaccruals	882	733
Current	43,012	42,315
Total Gross Loans	43,894	43,048
Farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	1,080	1,128
Total Gross Loans	1,080	1,128
Commercial Mortgages (Non-Owner Occupied)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccruals	1,045
Total Past Due and Nonaccruals	1,045
Current	20,873	20,534
Total Gross Loans	21,918	20,534
Commercial Mortgages (Owner Occupied)
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due	1,098
Nonaccruals	1,495	566
Total Past Due and Nonaccruals	2,593	566
Current	33,848	32,760
Total Gross Loans	36,441	33,326
Residential First Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due	1,383	1,270
90 Days or More Past Due and Still Accruing	323
Nonaccruals	900	359
Total Past Due and Nonaccruals	2,606	1,629
Current	147,616	133,638
Total Gross Loans	150,222	135,267
Residential Revolving and Junior Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due	152	6
Nonaccruals	115	31
Total Past Due and Nonaccruals	267	37
Current	26,095	25,363
Total Gross Loans	26,362	25,400
Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due	39	96
Nonaccruals	124	228
Total Past Due and Nonaccruals	163	324
Current	30,838	33,678
Total Gross Loans	31,001	34,002
Consumer and Other Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due	48	66
90 Days or More Past Due and Still Accruing	5	14
Nonaccruals		101
Total Past Due and Nonaccruals	53	181
Current	5,570	5,168
Total Gross Loans	$ 5,623	$ 5,349