Loans - Recorded Investment in Past Due and Non-accruing Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due	$ 1,906	$ 1,502
90 Days or More Past Due and Still Accruing	11	14
Nonaccruals	6,433	1,954
Total Past Due and Nonaccruals	8,350	3,470
Current	338,872	294,584
Total Gross Loans	347,222	298,054
Construction, Land and Land Development
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due	93	64
Nonaccruals	672	669
Total Past Due and Nonaccruals	765	733
Current	41,364	42,315
Total Gross Loans	42,129	43,048
Farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	1,030	1,128
Total Gross Loans	1,030	1,128
Commercial Mortgages (Non-Owner Occupied)
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due	264
Total Past Due and Nonaccruals	264
Current	28,822	20,534
Total Gross Loans	29,086	20,534
Commercial Mortgages (Owner Occupied)
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due	133
Nonaccruals	2,350	566
Total Past Due and Nonaccruals	2,483	566
Current	41,473	32,760
Total Gross Loans	43,956	33,326
Residential First Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due	1,304	1,270
Nonaccruals	2,841	359
Total Past Due and Nonaccruals	4,145	1,629
Current	160,260	133,638
Total Gross Loans	164,405	135,267
Residential Revolving and Junior Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due	70	6
Nonaccruals	277	31
Total Past Due and Nonaccruals	347	37
Current	26,150	25,363
Total Gross Loans	26,497	25,400
Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due	10	96
Nonaccruals	285	228
Total Past Due and Nonaccruals	295	324
Current	34,809	33,678
Total Gross Loans	35,104	34,002
Consumer and Other Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due	32	66
90 Days or More Past Due and Still Accruing	11	14
Nonaccruals	8	101
Total Past Due and Nonaccruals	51	181
Current	4,964	5,168
Total Gross Loans	$ 5,015	$ 5,349