Age Analysis of Past Due Loans, Segregated by Class (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-89 Days Past Due	$ 9,394	$ 9,528
Loans 90 or more Days Past Due	6,109	10,547
Total Past Due Loans	15,503	20,075
Current Loans	377,892	372,593
Total Gross Loans	390,395	392,668
Accruing Loans 90 or more Days Past Due	119	2,095
Real Estate Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-89 Days Past Due	8,180	8,131
Loans 90 or more Days Past Due	6,043	10,473
Total Past Due Loans	14,223	18,604
Current Loans	310,573	289,112
Total Gross Loans	321,796	307,716
Accruing Loans 90 or more Days Past Due	90	2,085
Real Estate Loans | Land Development and Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-89 Days Past Due	639	170
Total Past Due Loans	639	170
Current Loans	30,423	27,054
Total Gross Loans	31,062	27,224
Real Estate Loans | Farmland
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-89 Days Past Due	366	419
Loans 90 or more Days Past Due	71	69
Total Past Due Loans	437	488
Current Loans	29,660	29,146
Total Gross Loans	30,097	29,634
Real Estate Loans | 1-4 Family Mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-89 Days Past Due	4,827	4,234
Loans 90 or more Days Past Due	342	1,088
Total Past Due Loans	5,169	5,322
Current Loans	97,244	100,167
Total Gross Loans	102,413	105,489
Accruing Loans 90 or more Days Past Due	90	335
Real Estate Loans | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-89 Days Past Due	2,348	3,308
Loans 90 or more Days Past Due	5,630	9,316
Total Past Due Loans	4,978	12,624
Current Loans	153,246	132,745
Total Gross Loans	158,224	145,369
Accruing Loans 90 or more Days Past Due		1,750
Business Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-89 Days Past Due	195	253
Loans 90 or more Days Past Due	3	23
Total Past Due Loans	195	276
Current Loans	41,916	56,845
Total Gross Loans	42,111	57,121
Business Loans | Commercial and Industrial Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-89 Days Past Due	192	248
Loans 90 or more Days Past Due		23
Total Past Due Loans	192	271
Current Loans	40,779	55,542
Total Gross Loans	40,971	55,813
Business Loans | Farm Production and Other Farm Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-89 Days Past Due	3	5
Total Past Due Loans	3	5
Current Loans	1,137	1,303
Total Gross Loans	1,140	1,308
Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-89 Days Past Due	1,019	1,144
Loans 90 or more Days Past Due	66	51
Total Past Due Loans	1,085	1,195
Current Loans	25,403	26,636
Total Gross Loans	26,488	27,831
Accruing Loans 90 or more Days Past Due	29	10
Consumer Loans | Credit Cards
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-89 Days Past Due	26	39
Loans 90 or more Days Past Due	17	10
Total Past Due Loans	43	49
Current Loans	945	1,038
Total Gross Loans	988	1,087
Accruing Loans 90 or more Days Past Due	17	10
Consumer Loans | Other Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-89 Days Past Due	993	1,105
Loans 90 or more Days Past Due	49	41
Total Past Due Loans	1,042	1,146
Current Loans	24,458	25,598
Total Gross Loans	25,500	26,744
Accruing Loans 90 or more Days Past Due	$ 12