Note 4 - Investment Securities Available-for-Sale (Tables)

12 Months Ended

Dec. 31, 2016

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

			Gross		Gross		Estimated
December 31, 2016	Amortized		Unrealized		Unrealized		Fair
(dollars in thousands)	Cost		Gains		Losses		Value
U. S. agency securities	$	107,425	$	519	$	1,802	$	106,142
Residential mortgage backed securities		329,606		324		3,691		326,239
Municipal bonds		94,607		1,723		400		95,930
Corporate bonds		9,508		82		11		9,579
Other equity investments		218		-		-		218
	$	541,364	$	2,648	$	5,904	$	538,108

			Gross		Gross		Estimated
December 31, 2015	Amortized		Unrealized		Unrealized		Fair
(dollars in thousands)	Cost		Gains		Losses		Value
U. S. agency securities	$	56,775	$	477	$	277	$	56,975
Residential mortgage backed securities		299,709		692		3,160		297,241
Municipal bonds		114,253		4,131		3		118,381
Corporate bonds		15,090		-		152		14,938
Other equity investments		307		27		-		334
	$	486,134	$	5,327	$	3,592	$	487,869

Schedule of Unrealized Loss on Investments [Table Text Block]

			Less than				12 Months
			12 Months				or Greater				Total
			Estimated				Estimated				Estimated
December 31, 2016	Number of		Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(dollars in thousands)	Securities		Value		Losses		Value		Losses		Value		Losses
U. S. agency securities		27	$	88,991	$	1,764	$	3,768	$	38	$	92,759	$	1,802
Residential mortgage backed securities		112		232,347		3,110		19,402		581		251,749		3,691
Municipal bonds		16		34,743		400		-		-		34,743		400
Corporate bonds		2		4,998		11		-		-		4,998		11
		157	$	361,079	$	5,285	$	23,170	$	619	$	384,249	$	5,904

			Less than				12 Months
			12 Months				or Greater				Total
			Estimated				Estimated				Estimated
December 31, 2015	Number of		Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(dollars in thousands)	Securities		Value		Losses		Value		Losses		Value		Losses
U. S. agency securities		13	$	32,927	$	277	$	-	$	-	$	32,927	$	277
Residential mortgage backed securities		92		157,871		1,438		58,954		1,722		216,825		3,160
Municipal bonds		2		1,559		3		-		-		1,559		3
Corporate bonds		4		14,938		152		-		-		14,938		152
		111	$	207,295	$	1,870	$	58,954	$	1,722	$	266,249	$	3,592

Available-for-sale Securities [Table Text Block]

	December 31, 2016				December 31, 2015
	Amortized		Estimated		Amortized		Estimated
(dollars in thousands)	Cost		Fair Value		Cost		Fair Value
U. S. agency securities maturing:
One year or less	$	83,885	$	82,548	$	31,436	$	31,361
After one year through five years		20,736		20,897		18,826		19,047
Five years through ten years		2,804		2,697		6,513		6,567
Residential mortgage backed securities		329,606		326,239		299,709		297,241
Municipal bonds maturing:
One year or less		1,056		1,070		4,450		4,478
After one year through five years		45,808		46,865		41,213		43,720
Five years through ten years		46,668		46,839		66,001		67,398
After ten years		1,075		1,156		2,589		2,785
Corporate bonds
After one year through five years		8,008		8,079		15,090		14,938
After ten years		1,500		1,500		-		-
Other equity investments		218		218		307		334
	$	541,364	$	538,108	$	486,134	$	487,869

- Definition

Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities.

+ References + Details