Loan Portfolio Segment Balances (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 2,662,010	$ 2,531,128
Residential Mortgage | Residential Real Estate Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	595,180	523,364
Residential Construction | Residential Real Estate Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	118,316	120,314
Commercial Owner Occupied Real Estate | Commercial Real Estate Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	569,350	571,510
Commercial Investor Real Estate | Commercial Real Estate Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	518,029	456,888
Commercial Acquisition, Development and Construction | Commercial Real Estate Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	158,739	151,933
Commercial Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	332,670	346,708
Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	962	3,421
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 368,764	$ 356,990