Loans And Leases (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 1,184,142	$ 1,277,090	$ 1,307,586
Less deferred cost (unearned loan fees), net	1,024	1,132
Total loans and leases, net	1,184,441	1,277,049
Commercial construction, land and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	228,220	250,859
Other commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	391,197	424,690
Residential Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	13,624	13,509
Residential Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	228,588	245,180
Consumer Other Financing Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less unearned discount leases	(725)	(1,173)
Commercial, financial and agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	276,779	291,874	292,381
Commercial, financial and agricultural | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	266,015	278,032
Commercial, financial and agricultural | Agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	1,223	1,028
Commercial, financial and agricultural | Equipment leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	9,541	12,814
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	619,417	675,549	695,800
Commercial real estate | Commercial construction, land and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	228,220	250,859
Commercial real estate | Other commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	391,197	424,690
Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	242,212	258,689	265,805
Residential real estate | Residential Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	13,624	13,509
Residential real estate | Residential Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	228,588	245,180
Consumer Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	45,734	50,978	53,600
Consumer Portfolio Segment | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	41,151	44,713
Consumer Portfolio Segment | Consumer Other Financing Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 4,583	$ 6,265