Loans - Analysis of the Credit Risk Profile of Each Loan Class (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Financing Receivable, Recorded Investment [Line Items]
Total	$ 377,513	$ 383,594	$ 384,135
Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	44,305	43,524
Secured by 1-4 Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	145,628	134,964
Other Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	159,834	176,573
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	19,701	20,718
Consumer and Other Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	8,045	7,815
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	305,483	304,351
Pass [Member] \| Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	25,627	22,384
Pass [Member] \| Secured by 1-4 Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	130,940	120,692
Pass [Member] \| Other Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	122,778	134,701
Pass [Member] \| Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	18,163	18,831
Pass [Member] \| Consumer and Other Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	7,975	7,743
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	26,432	26,614
Special Mention [Member] \| Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	4,851	5,176
Special Mention [Member] \| Secured by 1-4 Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	6,461	6,055
Special Mention [Member] \| Other Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	14,259	14,513
Special Mention [Member] \| Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	791	798
Special Mention [Member] \| Consumer and Other Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	70	72
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	45,598	52,629
Substandard [Member] \| Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	13,827	15,964
Substandard [Member] \| Secured by 1-4 Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	8,227	8,217
Substandard [Member] \| Other Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	22,797	27,359
Substandard [Member] \| Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	747	1,089
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