Note 7 - Securities in a Continuous Unrealized Loss Position (Details)	Jun. 30, 2016 USD ($)	Dec. 31, 2015 USD ($)
US Government Agencies Debt Securities [Member]
No. of securities	2	32
Securities in an unrealized loss position less than 12 months, fair value	$ 2,000,000	$ 40,949,000
Securities in an unrealized loss position less than 12 months, unrealized losses	(1,000)	(418,000)
Securities in an unrealized loss position 12 months or longer, fair value	0	4,426,000
Securities in an unrealized loss position 12 months or longer, unrealized losses	0	(72,000)
Securities in an unrealized loss position, fair value	2,000,000	45,375,000
Securities in an unrealized loss position, unrealized losses	$ (1,000)	$ (490,000)
US States and Political Subdivisions Debt Securities [Member]
No. of securities	3	20
Securities in an unrealized loss position less than 12 months, fair value	$ 893,000	$ 6,646,000
Securities in an unrealized loss position less than 12 months, unrealized losses	(6,000)	(19,000)
Securities in an unrealized loss position 12 months or longer, fair value	503,000	1,555,000
Securities in an unrealized loss position 12 months or longer, unrealized losses	(1,000)	(12,000)
Securities in an unrealized loss position, fair value	1,396,000	8,201,000
Securities in an unrealized loss position, unrealized losses	$ (7,000)	$ (31,000)
Collateralized Mortgage Obligations [Member]
No. of securities	19	49
Securities in an unrealized loss position less than 12 months, fair value	$ 1,796,000	$ 28,372,000
Securities in an unrealized loss position less than 12 months, unrealized losses	(16,000)	(261,000)
Securities in an unrealized loss position 12 months or longer, fair value	17,362,000	26,354,000
Securities in an unrealized loss position 12 months or longer, unrealized losses	(150,000)	(917,000)
Securities in an unrealized loss position, fair value	19,158,000	54,726,000
Securities in an unrealized loss position, unrealized losses	$ (166,000)	$ (1,178,000)
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
No. of securities		62
Securities in an unrealized loss position less than 12 months, fair value		$ 90,796,000
Securities in an unrealized loss position less than 12 months, unrealized losses		(871,000)
Securities in an unrealized loss position 12 months or longer, fair value		1,403,000
Securities in an unrealized loss position 12 months or longer, unrealized losses		(49,000)
Securities in an unrealized loss position, fair value		92,199,000
Securities in an unrealized loss position, unrealized losses		$ (920,000)
Collateralized Debt Obligations [Member]
No. of securities	5	5
Securities in an unrealized loss position less than 12 months, fair value	$ 0	$ 0
Securities in an unrealized loss position less than 12 months, unrealized losses	0	0
Securities in an unrealized loss position 12 months or longer, fair value	2,024,000	2,193,000
Securities in an unrealized loss position 12 months or longer, unrealized losses	(942,000)	(897,000)
Securities in an unrealized loss position, fair value	2,024,000	2,193,000
Securities in an unrealized loss position, unrealized losses	$ (942,000)	$ (897,000)
Corporate Debt Securities [Member]
No. of securities	1	6
Securities in an unrealized loss position less than 12 months, fair value		$ 5,988
Securities in an unrealized loss position less than 12 months, unrealized losses		(95)
Securities in an unrealized loss position 12 months or longer, fair value	994,000	0
Securities in an unrealized loss position 12 months or longer, unrealized losses	(17,000)	0
Securities in an unrealized loss position, fair value	994,000	5,988
Securities in an unrealized loss position, unrealized losses	$ (17,000)	$ (95)
Equity Securities [Member]
No. of securities	15	19
Securities in an unrealized loss position less than 12 months, fair value	$ 2,408,000	$ 4,035,000
Securities in an unrealized loss position less than 12 months, unrealized losses	(135,000)	(695,000)
Securities in an unrealized loss position 12 months or longer, fair value	1,014,000	193,000
Securities in an unrealized loss position 12 months or longer, unrealized losses	(174,000)	(75,000)
Securities in an unrealized loss position, fair value	3,422,000	4,228,000
Securities in an unrealized loss position, unrealized losses	$ (309,000)	$ (770,000)
No. of securities	45	193
Securities in an unrealized loss position less than 12 months, fair value	$ 7,097,000	$ 176,786,000
Securities in an unrealized loss position less than 12 months, unrealized losses	(158,000)	(2,359,000)
Securities in an unrealized loss position 12 months or longer, fair value	21,897,000	36,124,000
Securities in an unrealized loss position 12 months or longer, unrealized losses	(1,284,000)	(2,022,000)
Securities in an unrealized loss position, fair value	28,994,000	212,910,000
Securities in an unrealized loss position, unrealized losses	$ (1,442,000)	$ (4,381,000)