Note 3 - Securities (Tables)

6 Months Ended

Jun. 30, 2015

Investments, Debt and Equity Securities [Abstract]

Available-for-sale Securities [Table Text Block]

			Gross		Gross
	Amortized		Unrealized		Unrealized			Fair
	Cost		Gains		Losses			Value
June 30, 2015
U.S. Government agency debt obligations	$	162,342,000	$	1,702,000	$	(2,336,000	)	$	161,708,000
Mortgage-backed securities		79,018,000		1,083,000		(260,000	)		79,841,000
Municipal general obligation bonds		119,609,000		824,000		(622,000	)		119,811,000
Municipal revenue bonds		10,051,000		102,000		(4,000	)		10,149,000
Other investments		1,940,000		0		(3,000	)		1,937,000
	$	372,960,000	$	3,711,000	$	(3,225,000	)	$	373,446,000
December 31, 2014
U.S. Government agency debt obligations	$	194,894,000	$	1,612,000	$	(3,038,000	)	$	193,468,000
Mortgage-backed securities		92,656,000		1,123,000		(218,000	)		93,561,000
Municipal general obligation bonds		132,347,000		1,042,000		(307,000	)		133,082,000
Municipal revenue bonds		10,769,000		117,000		(13,000	)		10,873,000
Other investments		1,925,000		3,000		0			1,928,000
	$	432,591,000	$	3,897,000	$	(3,576,000	)	$	432,912,000

Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Table Text Block]

	Less than 12 Months				12 Months or More				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Loss		Value		Loss		Value		Loss
June 30, 2015
U.S. Government agency debt obligations	$	2,986,000	$	13,000	$	74,876,000	$	2,323,000	$	77,862,000	$	2,336,000
Mortgage-backed securities		6,048,000		33,000		19,822,000		227,000		25,870,000		260,000
Municipal general obligation bonds		9,001,000		164,000		65,947,000		458,000		74,948,000		622,000
Municipal revenue bonds		0		0		2,305,000		4,000		2,305,000		4,000
Other investments		1,431,000		3,000		0		0		1,431,000		3,000
	$	19,466,000	$	213,000	$	162,950,000	$	3,012,000	$	182,416,000	$	3,225,000

	Less than 12 Months				12 Months or More				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Loss		Value		Loss		Value		Loss
December 31, 2014
U.S. Government agency debt obligations	$	81,891,000	$	202,000	$	74,120,000	$	2,836,000	$	156,011,000	$	3,038,000
Mortgage-backed securities		49,940,000		218,000		0		0		49,940,000		218,000
Municipal general obligation bonds		54,104,000		307,000		0		0		54,104,000		307,000
Municipal revenue bonds		4,644,000		13,000		0		0		4,644,000		13,000
Other investments		0		0		0		0		0		0
	$	190,579,000	$	740,000	$	74,120,000	$	2,836,000	$	264,699,000	$	3,576,000

Investments Classified by Contractual Maturity Date [Table Text Block]

	Weighted
	Average			Amortized		Fair
	Yield			Cost		Value
Due in 2015		0.88	%	$	6,702,000	$	6,707,000
Due in 2016 through 2020		1.42			135,850,000		135,897,000
Due in 2021 through 2025		3.13			65,615,000		65,485,000
Due in 2026 and beyond		3.55			83,835,000		83,579,000
Mortgage-backed securities		1.68			79,018,000		79,841,000
Other investments		2.52			1,940,000		1,937,000
		2.18	%	$	372,960,000	$	373,446,000