Loans - Information Relating to Loans (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	$ 1,262,912	$ 1,226,081
Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	62,766	60,736
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	499,070	486,828
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	582,576	569,331
Commercial and Financial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	70,779	61,903
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	47,231	46,930
Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	$ 490	$ 353