Note 4 - Loans and Allowance for Loan Losses (Detail) (USD $)	3 Months Ended	12 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 Troubled Debt Restructurings [Member]	Sep. 30, 2012 Troubled Debt Restructurings [Member]	Dec. 31, 2011 Troubled Debt Restructurings [Member]	Sep. 30, 2012 Commercial and Industrial [Member]	Dec. 31, 2011 Troubled Debt Restructurings Performing According to Modified Terms [Member]	Sep. 30, 2012 Unsecured [Member]	Dec. 31, 2011 Unsecured [Member]
Increase (Decrease) in Other Loans				$ 2,803,000
Change in Troubled Debt Restructurings		30.00%
Financing Receivable, Modifications, Number of Contracts						1
Financing Receivable, Allowance for Credit Losses, Write-downs			4,244,000
Percentage of Loan Portfolio	78.00%						97.00%	4.20%	3.98%
Impaired Financing Receivable, Related Allowance	2,078,000	655,000	2,206,000	2,206,000	655,000
Other Commitment	101	81
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	676
Minimum Loan Balance for Loans Evaluated by Risk Categories	$ 500