Note 3 - Investment Securities (Details) - Maturities - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Held-to-Maturity Securities:
Within one year	$ 3,951
Within one year	3,971
After 1 through 5 years	8,875
After 1 through 5 years	9,275
After 5 through 10 years	3,332
After 5 through 10 years	3,491
After 10 years	833
After 10 years	871
Mortgage-backed securities	1,697
Mortgage-backed securities	1,862
	18,688	$ 21,833
	19,470	22,870
Available-for-Sale Securities:
Within one year	9,117
Within one year	9,324
After 1 through 5 years	37,545
After 1 through 5 years	38,935
After 5 through 10 years	143,566
After 5 through 10 years	148,642
After 10 years	220,659
After 10 years	230,592
Mortgage-backed securities	320,203
Mortgage-backed securities	324,543
	731,090
	$ 752,036	$ 774,145