Risk Category of Loans (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment [Line Items]
Gross loans	$ 462,544	$ 420,636
Commercial & Industrial Loans
Financing Receivable, Recorded Investment [Line Items]
Gross loans	93,893	94,876
Construction & Development
Financing Receivable, Recorded Investment [Line Items]
Gross loans	66,709	51,078
Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	250,160	231,819
Residential Real Estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	49,841	40,826
Consumer Loan
Financing Receivable, Recorded Investment [Line Items]
Gross loans	1,941	2,037
Pass
Financing Receivable, Recorded Investment [Line Items]
Gross loans	434,874	388,339
Pass | Commercial & Industrial Loans
Financing Receivable, Recorded Investment [Line Items]
Gross loans	85,196	84,109
Pass | Construction & Development
Financing Receivable, Recorded Investment [Line Items]
Gross loans	66,038	48,687
Pass | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	234,314	214,339
Pass | Residential Real Estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	47,591	39,391
Pass | Consumer Loan
Financing Receivable, Recorded Investment [Line Items]
Gross loans	1,735	1,813
Watch
Financing Receivable, Recorded Investment [Line Items]
Gross loans	6,276	10,135
Watch | Commercial & Industrial Loans
Financing Receivable, Recorded Investment [Line Items]
Gross loans	3,405	5,644
Watch | Construction & Development
Financing Receivable, Recorded Investment [Line Items]
Gross loans	262	1,154
Watch | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	1,847	1,820
Watch | Residential Real Estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	575	1,293
Watch | Consumer Loan
Financing Receivable, Recorded Investment [Line Items]
Gross loans	187	224
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Gross loans	12,574	14,012
Special Mention | Commercial & Industrial Loans
Financing Receivable, Recorded Investment [Line Items]
Gross loans	3,752	4,383
Special Mention | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	8,078	9,629
Special Mention | Residential Real Estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	725
Special Mention | Consumer Loan
Financing Receivable, Recorded Investment [Line Items]
Gross loans	19
Substandard
Financing Receivable, Recorded Investment [Line Items]
Gross loans	7,719	8,150
Substandard | Commercial & Industrial Loans
Financing Receivable, Recorded Investment [Line Items]
Gross loans	1,540	740
Substandard | Construction & Development
Financing Receivable, Recorded Investment [Line Items]
Gross loans	409	1,237
Substandard | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	4,820	6,031
Substandard | Residential Real Estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	950	142
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Gross loans	1,101
Doubtful | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	$ 1,101