Note 2 - Securities - Available-for-sale Securities (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
US Government Agencies Debt Securities [Member]
Amortized Cost	$ 138,133,000	$ 146,660,000
Gross Unrealized Gains	391,000	1,932,000
Gross Unrealized Losses	(641,000)	(1,552,000)
Fair Value	137,883,000	147,040,000
Collateralized Mortgage Backed Securities [Member]
Amortized Cost	51,671,000	66,670,000
Gross Unrealized Gains	956,000	708,000
Gross Unrealized Losses	(58,000)	(304,000)
Fair Value	52,569,000	67,074,000
Municipal General Obligation Bonds [Member]
Amortized Cost	122,293,000	120,679,000
Gross Unrealized Gains	2,357,000	1,549,000
Gross Unrealized Losses	(164,000)	(205,000)
Fair Value	124,486,000	122,023,000
Municipal Revenue Bonds [Member]
Amortized Cost	8,458,000	8,841,000
Gross Unrealized Gains	70,000	76,000
Gross Unrealized Losses	(10,000)	(3,000)
Fair Value	8,518,000	8,914,000
Other Debt Obligations [Member]
Amortized Cost	1,970,000	1,946,000
Gross Unrealized Gains	17,000	0
Gross Unrealized Losses	0	(5,000)
Fair Value	1,987,000	1,941,000
Amortized Cost	322,525,000	344,796,000
Gross Unrealized Gains	3,791,000	4,265,000
Gross Unrealized Losses	(873,000)	(2,069,000)
Fair Value	$ 325,443,000	$ 346,992,000