Loans - Analysis of the Credit Risk Profile of Each Loan Class (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
Financing Receivable, Recorded Investment [Line Items]
Total	$ 366,827	$ 383,594	$ 380,752
Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	34,404	43,524
Secured by 1-4 Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	142,446	134,964
Other Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	156,691	176,573
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	21,316	20,718
Consumer and Other Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	11,970	7,815
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	304,503	304,351
Pass [Member] \| Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	21,157	22,384
Pass [Member] \| Secured by 1-4 Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	131,597	120,692
Pass [Member] \| Other Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	119,862	134,701
Pass [Member] \| Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	19,917	18,831
Pass [Member] \| Consumer and Other Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	11,970	7,743
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	23,226	26,614
Special Mention [Member] \| Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	2,190	5,176
Special Mention [Member] \| Secured by 1-4 Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	4,692	6,055
Special Mention [Member] \| Other Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	15,638	14,513
Special Mention [Member] \| Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	706	798
Special Mention [Member] \| Consumer and Other Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total		72
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	39,098	52,629
Substandard [Member] \| Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	11,057	15,964
Substandard [Member] \| Secured by 1-4 Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	6,157	8,217
Substandard [Member] \| Other Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	21,191	27,359
Substandard [Member] \| Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	693	1,089
Substandard [Member] \| Consumer and Other Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total
Doubtful [Member] \| Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total
Doubtful [Member] \| Secured by 1-4 Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Total
Doubtful [Member] \| Other Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total
Doubtful [Member] \| Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total
Doubtful [Member] \| Consumer and Other Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total