Loans - Risk Category, Class of Loans and Recorded Investment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	$ 1,304,207	$ 1,226,081
Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	67,450	60,736
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	520,382	486,828
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	592,746	569,331
Commercial and Financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	78,636	61,903
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	44,993	47,283
Pass [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	1,224,242	1,103,938
Pass [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	63,186	54,994
Pass [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	485,268	414,023
Pass [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	554,681	527,891
Pass [Member] | Commercial and Financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	77,840	61,123
Pass [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	43,267	45,907
Special Mention [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	8,899	16,577
Special Mention [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	583	1,717
Special Mention [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	6,810	12,137
Special Mention [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	824	1,686
Special Mention [Member] | Commercial and Financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	382	587
Special Mention [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	300	450
Substandard [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	18,257	22,665
Substandard [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	0	0
Substandard [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	15,886	22,180
Substandard [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	1,670	36
Substandard [Member] | Commercial and Financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	248	193
Substandard [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	453	256
Doubtful [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	0	0
Doubtful [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	0	0
Doubtful [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	0	0
Doubtful [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	0	0
Doubtful [Member] | Commercial and Financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	0	0
Doubtful [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	0	0
Nonaccrual [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	27,672	40,955
Nonaccrual [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	1,302	1,342
Nonaccrual [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	5,111	17,234
Nonaccrual [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	20,705	22,099
Nonaccrual [Member] | Commercial and Financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	13	0
Nonaccrual [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	541	280
Pass-Troubled Debt Restructures [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	7,452	8,616
Pass-Troubled Debt Restructures [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	1,838	2,103
Pass-Troubled Debt Restructures [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	5,584	6,513
Pass-Troubled Debt Restructures [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	30	0
Pass-Troubled Debt Restructures [Member] | Commercial and Financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	0	0
Pass-Troubled Debt Restructures [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	0	0
Troubled Debt Restructures [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	17,685	33,330
Troubled Debt Restructures [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	541	580
Troubled Debt Restructures [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	1,723	14,741
Troubled Debt Restructures [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	14,836	17,619
Troubled Debt Restructures [Member] | Commercial and Financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	153	0
Troubled Debt Restructures [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	$ 432	$ 390