Note 1 - Summary of Significant Accounting Policies (Details) - Net Income Per Common Share - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net Income Per Common Share [Abstract]
Net income, basic and diluted	$ 3,584	$ 3,832	$ 3,502	$ 4,074	$ 4,158	$ 4,107	$ 4,824	$ 3,370	$ 14,992	$ 16,459	$ 13,446
Less preferred stock dividends and discount accretion	0	0	170	225	377	450	563	537	395	1,927	1,951
Net income available to common shareholders, basic and diluted	$ 3,584	$ 3,832	$ 3,332	$ 3,849	$ 3,781	$ 3,657	$ 4,261	$ 2,833	$ 14,597	$ 14,532	$ 11,495
Average common shares outstanding, basic and diluted (in Shares)	7,497	7,495	7,492	7,490	7,487	7,485	7,482	7,479	7,494	7,483	7,474
Net income per common share, basic and diluted (in Dollars per share)	$ 0.48	$ 0.51	$ 0.44	$ 0.51	$ 0.51	$ 0.49	$ 0.57	$ 0.38	$ 1.95	$ 1.94	$ 1.54