Note 4 - Loans and Allowance for Credit Losses (Detail) - TDR Loan Modifications By Portfolio Segment (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Number Of Contracts	5	6
TDRs	$ 9,980	$ 13,873
Performing Financing Receivable [Member] | Commercial Loan [Member]
TDRs	2,000	4,977
Performing Financing Receivable [Member] | Commercial Real Estate Investment [Member]
TDRs	2,142	3,543
Performing Financing Receivable [Member] | Construction, Commercial And Residential [Member]
TDRs	4,641	5,353
Performing Financing Receivable [Member]
TDRs	8,783	13,873
Nonperforming Financing Receivable [Member] | Commercial Real Estate Investment [Member]
TDRs	217
Nonperforming Financing Receivable [Member] | Construction, Commercial And Residential [Member]
TDRs	980
Nonperforming Financing Receivable [Member]
TDRs	1,197
Commercial Loan [Member]
Number Of Contracts	1	2
TDRs	2,000	4,977
Commercial Real Estate Investment [Member]
Number Of Contracts	2	2
TDRs	2,359	3,543
Construction, Commercial And Residential [Member]
Number Of Contracts	2	2
TDRs	$ 5,621	$ 5,353