Loans and Allowance for Loan Losses - Loans by Credit Quality Indicators (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	$ 1,053,243,000	$ 1,041,189,000	$ 1,072,422,000
Commercial and Industrial [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	286,373,000	285,322,000
Commercial and Industrial [Member] \| Grades 1-4 [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	208,151,000	180,314,000
Commercial and Industrial [Member] \| Grades 5-7 [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	76,237,000	101,832,000
Commercial and Industrial [Member] \| Grades 8-9 [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	1,985,000	3,176,000
Commercial Vacant Land, Land Development, and Residential Construction [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	36,741,000	48,099,000
Commercial Vacant Land, Land Development, and Residential Construction [Member] \| Grades 1-4 [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	6,973,000	6,526,000
Commercial Vacant Land, Land Development, and Residential Construction [Member] \| Grades 5-7 [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	25,535,000	37,697,000
Commercial Vacant Land, Land Development, and Residential Construction [Member] \| Grades 8-9 [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	4,233,000	3,876,000
Commercial Real Estate - Owner Occupied [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	261,877,000	259,277,000
Commercial Real Estate - Owner Occupied [Member] \| Grades 1-4 [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	156,230,000	150,467,000
Commercial Real Estate - Owner Occupied [Member] \| Grades 5-7 [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	103,066,000	102,988,000
Commercial Real Estate - Owner Occupied [Member] \| Grades 8-9 [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	2,581,000	5,822,000
Commercial Real Estate - Non-Owner Occupied [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	364,066,000	324,886,000
Commercial Real Estate - Non-Owner Occupied [Member] \| Grades 1-4 [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	219,325,000	154,127,000
Commercial Real Estate - Non-Owner Occupied [Member] \| Grades 5-7 [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	122,717,000	128,041,000
Commercial Real Estate - Non-Owner Occupied [Member] \| Grades 8-9 [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	22,024,000	42,718,000
Commercial Real Estate - Multi-Family and Residential Rental [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	37,639,000	50,922,000
Commercial Real Estate - Multi-Family and Residential Rental [Member] \| Grades 1-4 [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	15,465,000	24,015,000
Commercial Real Estate - Multi-Family and Residential Rental [Member] \| Grades 5-7 [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	19,469,000	22,082,000
Commercial Real Estate - Multi-Family and Residential Rental [Member] \| Grades 8-9 [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	2,705,000	4,825,000
Retail Home Equity and Other [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	35,080,000	38,917,000
Retail 1-4 Family Mortgages [Member]
Financing Receivable Credit Quality Indicator [Line Items]
Total loans	$ 31,467,000	$ 33,766,000