Note 3 - Securities (Tables)

12 Months Ended

Dec. 31, 2015

Investments, Debt and Equity Securities [Abstract]

Available-for-sale Securities [Table Text Block]

	December 31, 2015
Available for sale:	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
U.S. Government agencies and corporations	$	216,897	$	519	$	4,952	$	212,464
States and political subdivisions		15,934		541		---		16,475
Mortgage-backed securities		1,199		120		---		1,319
Corporate debt securities		6,015		22		291		5,746
Other securities		189		---		62		127
Total securities available for sale	$	240,234	$	1,202	$	5,305	$	236,131

	December 31, 2014
Available for sale:	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
U.S. Government agencies and corporations	$	197,740	$	973	$	4,494	$	194,219
States and political subdivisions		18,529		851		---		19,380
Mortgage-backed securities		1,830		184		---		2,014
Corporate debt securities		6,991		140		27		7,104
Other securities		189		---		62		127
Total securities available for sale	$	225,279	$	2,148	$	4,583	$	222,844

Investments Classified by Contractual Maturity Date [Table Text Block]

	December 31, 2015
Available for sale:	Amortized Cost		Fair Value
Due in one year or less	$	974	$	992
Due after one year through five years		68,172		68,177
Due after five years through ten years		32,062		31,836
Due after ten years		138,837		134,999
No maturity		189		127
	$	240,234	$	236,131

	December 31, 2015
Held to maturity:	Amortized Cost		Fair Value
Due in one year or less	$	1,160	$	1,168
Due after one year through five years		13,011		13,849
Due after five years through ten years		21,288		22,317
Due after ten years		116,569		120,698
	$	152,028	$	158,032

Held-to-maturity Securities [Table Text Block]

	December 31, 2015
Held to maturity:	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
U.S. Government agencies and corporations	$	13,909	$	288	$	177	$	14,020
States and political subdivisions		136,373		6,179		330		142,222
Mortgage-backed securities		327		36		---		363
Corporate debt securities		1,419		10		2		1,427
Total securities held to maturity	$	152,028	$	6,513	$	509	$	158,032

	December 31, 2014
Held to maturity:	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
U.S. Government agencies and corporations	$	18,922	$	350	$	245	$	19,027
States and political subdivisions		140,702		6,823		727		146,798
Mortgage-backed securities		415		51		---		466
Corporate debt securities		1,413		1		2		1,412
Total securities held to maturity	$	161,452	$	7,225	$	974	$	167,703

Schedule of Temporary Impairment Losses, Investments [Table Text Block]

	December 31, 2015
	Less Than 12 Months				12 Months or More
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
U. S. Government agencies and corporations	$	88,255	$	1,800	$	84,959	$	3,329
State and political subdivisions		3,449		24		10,161		306
Corporate debt securities		4,974		292		200		1
Other securities		---		---		127		62
Total temporarily impaired securities	$	96,678	$	2,116	$	95,447	$	3,698

	December 31, 2014
	Less Than 12 Months				12 Months or More
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
U. S. Government agencies and corporations	$	6,964	$	30	$	156,149	$	4,709
State and political subdivisions		1,222		35		19,818		692
Corporate debt securities		450		2		1,948		27
Other securities		---		---		127		62
Total temporarily impaired securities	$	8,636	$	67	$	178,042	$	5,490