Note 7 - Fair Value Measurements (Detail) - Fair Value of Financial Assets and Liabililties Measure on Non-Recurring Basis (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Impaired loans, net of valuation allowance	$ 1,100	$ 1,130
Other real estate owned	9,440	8,938	9,207	9,562
Fair Value, Inputs, Level 2 [Member]
Impaired loans, net of valuation allowance	52	62
Other real estate owned	5,009	4,382
Fair Value, Inputs, Level 3 [Member]
Impaired loans, net of valuation allowance	1,048	1,068
Other real estate owned	$ 4,431	$ 4,556