Note 4 - Securities (Tables)

12 Months Ended

Dec. 31, 2016

Notes Tables

Schedule of Available-for-sale Securities Reconciliation [Table Text Block]

(in thousands)	Amortized		Unrealized
December 31, 2016	cost		Gains		Losses		Fair value
U.S. Treasury and other U.S. government obligations	$	74,997	$	1	$	-	$	74,998
Government sponsored enterprise obligations		268,784		800		1,494		268,090
Mortgage-backed securities - government agencies		170,344		735		2,236		168,843
Obligations of states and political subdivisions		57,158		682		396		57,444
Corporate equity securities		653		46		-		699
Total securities available-for-sale	$	571,936	$	2,264	$	4,126	$	570,074

(in thousands)	Amortized		Unrealized
December 31, 2015	cost		Gains		Losses		Fair value
U.S. Treasury and other U.S. government obligations	$	79,999	$	1	$	-	$	80,000
Government sponsored enterprise obligations		251,190		1,468		765		251,893
Mortgage-backed securities - government agencies		170,139		1,143		1,654		169,628
Obligations of states and political subdivisions		62,410		1,342		50		63,702
Corporate equity securities		653		-		-		653
Total securities available-for-sale	$	564,391	$	3,954	$	2,469	$	565,876

Investments Classified by Contractual Maturity Date [Table Text Block]

(in thousands)
Securities available-for-sale	Amortized cost		Fair value
Due within 1 year	$	176,860	$	177,024
Due after 1 but within 5 years		99,551		99,637
Due after 5 but within 10 years		17,129		16,881
Due after 10 years		107,399		106,990
Corporate equity security		653		699
Mortgage-backed securities - government agencies		170,344		168,843
Total securities available for sale	$	571,936	$	570,074

Schedule of Unrealized Loss on Investments [Table Text Block]

(in thousands)	Less than 12 months				12 months or more				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
December 31, 2016	value		losses		value		losses		value		losses
Government sponsored enterprise obligations	$	154,951	$	1,344	$	3,485	$	150	$	158,436	$	1,494
Mortgage-backed securities - government agencies		115,374		1,873		9,914		363		125,288		2,236
Obligations of states and political subdivisions		29,893		380		1,478		16		31,371		396
Total temporarily impaired securities	$	300,218	$	3,597	$	14,877	$	529	$	315,095	$	4,126
December 31, 2015
Government sponsored enterprise obligations	$	102,098	$	500	$	8,469	$	265	$	110,567	$	765
Mortgage-backed securities - government agencies		49,774		662		29,936		992		79,710		1,654
Obligations of states and political subdivisions		13,225		31		1,955		19		15,180		50
Total temporarily impaired securities	$	165,097	$	1,193	$	40,360	$	1,276	$	205,457	$	2,469