Note 3 - Investment Securities (Details) - Securities in a Continuous Unrealized Loss Position - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Note 3 - Investment Securities (Details) - Securities in a Continuous Unrealized Loss Position [Line Items]
Available for sale securities in a continuous unrealized loss position, less than 12 months, fair value	$ 146,024	$ 27,506
Available for sale securities in a continuous unrealized loss position, less than 12 months, unrealized losses	4,086	142
Available for sale securities in a continuous unrealized loss position, 12 months or more, fair value	12,151	5,657
Available for sale securities in a continuous unrealized loss position, 12 months or more, unrealized losses	1,310	2,129
Available for sale securities in a continuous unrealized loss position, fair value	158,175	33,163
Available for sale securities in a continuous unrealized loss position, unrealized losses	5,396	2,271
Held to maturity securities in a continuous unrealized loss position, less than 12 months, fair value	88,553	19,766
Held to maturity securities in a continuous unrealized loss position, less than 12 months, unrealized losses	825	92
Held to maturity securities in a continuous unrealized loss position, 12 months or more, fair value	15,956	9,232
Held to maturity securities in a continuous unrealized loss position, 12 months or more, unrealized losses	48	52
Held to maturity securities in a continuous unrealized loss position, fair value	104,509	28,998
Held to maturity securities in a continuous unrealized loss position, unrealized losses	873	144
Collateralized Mortgage Obligations [Member]
Note 3 - Investment Securities (Details) - Securities in a Continuous Unrealized Loss Position [Line Items]
Available for sale securities in a continuous unrealized loss position, less than 12 months, fair value	116,161	17,331
Available for sale securities in a continuous unrealized loss position, less than 12 months, unrealized losses	3,173	96
Available for sale securities in a continuous unrealized loss position, 12 months or more, fair value	0	0
Available for sale securities in a continuous unrealized loss position, 12 months or more, unrealized losses	0	0
Available for sale securities in a continuous unrealized loss position, fair value	116,161	17,331
Available for sale securities in a continuous unrealized loss position, unrealized losses	3,173	96
Held to maturity securities in a continuous unrealized loss position, less than 12 months, fair value	68,888	19,766
Held to maturity securities in a continuous unrealized loss position, less than 12 months, unrealized losses	732	92
Held to maturity securities in a continuous unrealized loss position, 12 months or more, fair value	15,956	9,232
Held to maturity securities in a continuous unrealized loss position, 12 months or more, unrealized losses	48	52
Held to maturity securities in a continuous unrealized loss position, fair value	84,844	28,998
Held to maturity securities in a continuous unrealized loss position, unrealized losses	780	144
Collateralized Mortgage Backed Securities [Member]
Note 3 - Investment Securities (Details) - Securities in a Continuous Unrealized Loss Position [Line Items]
Available for sale securities in a continuous unrealized loss position, less than 12 months, fair value	2,389	3,997
Available for sale securities in a continuous unrealized loss position, less than 12 months, unrealized losses	14	2
Available for sale securities in a continuous unrealized loss position, 12 months or more, fair value	5,502	1,069
Available for sale securities in a continuous unrealized loss position, 12 months or more, unrealized losses	64	31
Available for sale securities in a continuous unrealized loss position, fair value	7,891	5,066
Available for sale securities in a continuous unrealized loss position, unrealized losses	78	33
Held to maturity securities in a continuous unrealized loss position, less than 12 months, fair value	7,711
Held to maturity securities in a continuous unrealized loss position, less than 12 months, unrealized losses	21
Held to maturity securities in a continuous unrealized loss position, 12 months or more, fair value	0
Held to maturity securities in a continuous unrealized loss position, 12 months or more, unrealized losses	0
Held to maturity securities in a continuous unrealized loss position, fair value	7,711
Held to maturity securities in a continuous unrealized loss position, unrealized losses	21
US States and Political Subdivisions Debt Securities [Member]
Note 3 - Investment Securities (Details) - Securities in a Continuous Unrealized Loss Position [Line Items]
Available for sale securities in a continuous unrealized loss position, less than 12 months, fair value	886	1,298
Available for sale securities in a continuous unrealized loss position, less than 12 months, unrealized losses	15	10
Available for sale securities in a continuous unrealized loss position, 12 months or more, fair value	1,814	1,395
Available for sale securities in a continuous unrealized loss position, 12 months or more, unrealized losses	17	30
Available for sale securities in a continuous unrealized loss position, fair value	2,700	2,693
Available for sale securities in a continuous unrealized loss position, unrealized losses	32	40
Corporate Debt Securities [Member]
Note 3 - Investment Securities (Details) - Securities in a Continuous Unrealized Loss Position [Line Items]
Available for sale securities in a continuous unrealized loss position, less than 12 months, fair value	9,583	4,880
Available for sale securities in a continuous unrealized loss position, less than 12 months, unrealized losses	258	34
Available for sale securities in a continuous unrealized loss position, 12 months or more, fair value	2,952	0
Available for sale securities in a continuous unrealized loss position, 12 months or more, unrealized losses	42	0
Available for sale securities in a continuous unrealized loss position, fair value	12,535	4,880
Available for sale securities in a continuous unrealized loss position, unrealized losses	300	34
Asset-backed Securities [Member]
Note 3 - Investment Securities (Details) - Securities in a Continuous Unrealized Loss Position [Line Items]
Available for sale securities in a continuous unrealized loss position, less than 12 months, fair value	17,005
Available for sale securities in a continuous unrealized loss position, less than 12 months, unrealized losses	626
Available for sale securities in a continuous unrealized loss position, 12 months or more, fair value	0
Available for sale securities in a continuous unrealized loss position, 12 months or more, unrealized losses	0
Available for sale securities in a continuous unrealized loss position, fair value	17,005
Available for sale securities in a continuous unrealized loss position, unrealized losses	626
Collateralized Debt Obligations [Member]
Note 3 - Investment Securities (Details) - Securities in a Continuous Unrealized Loss Position [Line Items]
Available for sale securities in a continuous unrealized loss position, less than 12 months, fair value	0	0
Available for sale securities in a continuous unrealized loss position, less than 12 months, unrealized losses	0	0
Available for sale securities in a continuous unrealized loss position, 12 months or more, fair value	1,883	3,193
Available for sale securities in a continuous unrealized loss position, 12 months or more, unrealized losses	1,187	2,068
Available for sale securities in a continuous unrealized loss position, fair value	1,883	3,193
Available for sale securities in a continuous unrealized loss position, unrealized losses	1,187	$ 2,068
US Government Agencies Debt Securities [Member]
Note 3 - Investment Securities (Details) - Securities in a Continuous Unrealized Loss Position [Line Items]
Held to maturity securities in a continuous unrealized loss position, less than 12 months, fair value	11,954
Held to maturity securities in a continuous unrealized loss position, less than 12 months, unrealized losses	72
Held to maturity securities in a continuous unrealized loss position, 12 months or more, fair value	0
Held to maturity securities in a continuous unrealized loss position, 12 months or more, unrealized losses	0
Held to maturity securities in a continuous unrealized loss position, fair value	11,954
Held to maturity securities in a continuous unrealized loss position, unrealized losses	$ 72