Summary Of Financial Instruments With Off-Balance Sheet Credit Risk (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Disclosure Summary Of Financial Instruments With Off Balance Sheet Credit Risk [Line Items]
Total Commitments to extend credit and available credit lines	$ 1,068,764	$ 1,061,133
Commercial
Disclosure Summary Of Financial Instruments With Off Balance Sheet Credit Risk [Line Items]
Total Commitments to extend credit and available credit lines	184,083	186,014
Real estate-development and construction
Disclosure Summary Of Financial Instruments With Off Balance Sheet Credit Risk [Line Items]
Total Commitments to extend credit and available credit lines	100,826	79,480
Real estate-residential mortgage
Disclosure Summary Of Financial Instruments With Off Balance Sheet Credit Risk [Line Items]
Total Commitments to extend credit and available credit lines	13,908	56,445
Lines of credit, principally home equity and business lines
Disclosure Summary Of Financial Instruments With Off Balance Sheet Credit Risk [Line Items]
Total Commitments to extend credit and available credit lines	710,202	667,186
Standby letters of credit
Disclosure Summary Of Financial Instruments With Off Balance Sheet Credit Risk [Line Items]
Total Commitments to extend credit and available credit lines	$ 59,745	$ 72,008