Note 2 - Securities - Available-for-sale Securities (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
US Government Agencies Debt Securities [Member]
Amortized Cost	$ 132,085,000	$ 146,660,000
Gross Unrealized Gains	895,000	1,932,000
Gross Unrealized Losses	(38,000)	(1,552,000)
Fair Value	132,942,000	147,040,000
Collateralized Mortgage Backed Securities [Member]
Amortized Cost	56,616,000	66,670,000
Gross Unrealized Gains	979,000	708,000
Gross Unrealized Losses	(50,000)	(304,000)
Fair Value	57,545,000	67,074,000
Municipal General Obligation Bonds [Member]
Amortized Cost	119,878,000	120,679,000
Gross Unrealized Gains	2,602,000	1,549,000
Gross Unrealized Losses	(94,000)	(205,000)
Fair Value	122,386,000	122,023,000
Municipal Revenue Bonds [Member]
Amortized Cost	8,498,000	8,841,000
Gross Unrealized Gains	95,000	76,000
Gross Unrealized Losses	0	(3,000)
Fair Value	8,593,000	8,914,000
Other Debt Obligations [Member]
Amortized Cost	1,962,000	1,946,000
Gross Unrealized Gains	24,000	0
Gross Unrealized Losses	0	(5,000)
Fair Value	1,986,000	1,941,000
Amortized Cost	319,039,000	344,796,000
Gross Unrealized Gains	4,595,000	4,265,000
Gross Unrealized Losses	(182,000)	(2,069,000)
Fair Value	$ 323,452,000	$ 346,992,000