Note 11 - Fair Values (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis - USD ($)		Mar. 31, 2016	Dec. 31, 2015
Available for sale securities
Available for sale securities	[1]	$ 343,805,000	$ 346,992,000
Fair Value, Measurements, Recurring [Member]
Available for sale securities
Total		343,531,000	346,739,000
US Government Agencies Debt Securities [Member]
Available for sale securities
Available for sale securities		142,896,000	147,040,000
US Government Agencies Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		142,896,000	147,040,000
Collateralized Mortgage Backed Securities [Member]
Available for sale securities
Available for sale securities		62,461,000	67,074,000
Collateralized Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		62,461,000	67,074,000
Municipal General Obligation Bonds [Member]
Available for sale securities
Available for sale securities		127,594,000	122,023,000
Municipal General Obligation Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		127,594,000	122,023,000
Municipal Revenue Bonds [Member]
Available for sale securities
Available for sale securities		8,885,000	8,914,000
Municipal Revenue Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		8,885,000	8,914,000
Other Debt Obligations [Member]
Available for sale securities
Available for sale securities		1,969,000	1,941,000
Other Debt Obligations [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		1,969,000	1,941,000
Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Interest rate swap		(274,000)	(253,000)
Fair Value, Inputs, Level 1 [Member]
Available for sale securities
Available for sale securities		0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Total		0	0
Fair Value, Inputs, Level 1 [Member] | US Government Agencies Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		0	0
Fair Value, Inputs, Level 1 [Member] | Collateralized Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		0	0
Fair Value, Inputs, Level 1 [Member] | Municipal General Obligation Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		0	0
Fair Value, Inputs, Level 1 [Member] | Municipal Revenue Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		0	0
Fair Value, Inputs, Level 1 [Member] | Other Debt Obligations [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		0	0
Fair Value, Inputs, Level 1 [Member] | Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Interest rate swap		0	0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Total		335,112,000	338,320,000
Fair Value, Inputs, Level 2 [Member] | US Government Agencies Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		142,896,000	147,040,000
Fair Value, Inputs, Level 2 [Member] | Collateralized Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		62,461,000	67,074,000
Fair Value, Inputs, Level 2 [Member] | Municipal General Obligation Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		119,175,000	113,604,000
Fair Value, Inputs, Level 2 [Member] | Municipal Revenue Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		8,885,000	8,914,000
Fair Value, Inputs, Level 2 [Member] | Other Debt Obligations [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		1,969,000	1,941,000
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Interest rate swap		(274,000)	(253,000)
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Total		8,419,000	8,419,000
Fair Value, Inputs, Level 3 [Member] | US Government Agencies Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		0	0
Fair Value, Inputs, Level 3 [Member] | Collateralized Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		0	0
Fair Value, Inputs, Level 3 [Member] | Municipal General Obligation Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		8,419,000	8,419,000
Fair Value, Inputs, Level 3 [Member] | Municipal Revenue Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		0	0
Fair Value, Inputs, Level 3 [Member] | Other Debt Obligations [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Available for sale securities		0	0
Fair Value, Inputs, Level 3 [Member] | Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member]
Available for sale securities
Interest rate swap		$ 0	$ 0

[1] See Note 11 for a description of the fair value hierarchy as well as a disclosure of levels for classes of financial assets and liabilities.