Note 3 - Investment Securities Available for Sale (Detail) - Gross Unrealized Losses and Fair Value of the Investments (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Securities in Unrealized Loss Position Less Than 12 Months Fair Value	$ 5,967	$ 5,622
Securities in Unrealized Loss Position Less Than 12 Months Unrealized Losses	24	200
Securities in Unrealized Loss Position 12 Months or More Fair Value	3,921
Securities in Unrealized Loss Position 12 Months or More Unrealized Losses	79
Securities in Unrealized Loss Position Fair Value	9,888	5,622
Securities in Unrealized Loss Position Unrealized Losses	103	200
US States and Political Subdivisions Debt Securities [Member]
Securities in Unrealized Loss Position Less Than 12 Months Fair Value	1,975	1,812
Securities in Unrealized Loss Position Less Than 12 Months Unrealized Losses	16	10
Securities in Unrealized Loss Position Fair Value	1,975	1,812
Securities in Unrealized Loss Position Unrealized Losses	16	10
Corporate Debt Securities [Member]
Securities in Unrealized Loss Position Less Than 12 Months Fair Value	3,992	3,810
Securities in Unrealized Loss Position Less Than 12 Months Unrealized Losses	8	190
Securities in Unrealized Loss Position 12 Months or More Fair Value	3,921
Securities in Unrealized Loss Position 12 Months or More Unrealized Losses	79
Securities in Unrealized Loss Position Fair Value	7,913	3,810
Securities in Unrealized Loss Position Unrealized Losses	$ 87	$ 190