Note 4 - Investment Securities Available for Sale (Details) - Securities in a Continuous Loss Position (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Note 4 - Investment Securities Available for Sale (Details) - Securities in a Continuous Loss Position [Line Items]
Securities in continuous unrealized loss position, less than 12 months, fair value	$ 94,440	$ 44,855
Securities in continuous unrealized loss position, less than 12 months, unrealized losses	410	623
Securities in continuous unrealized loss position, 12 months or more, fair value	1,028	945
Securities in continuous unrealized loss position, 12 months or more, unrealized losses	17	54
Securities in continuous unrealized loss position, fair value	95,468	45,800
Securities in continuous unrealized loss position, unrealized losses	427	677
US Treasury and Government [Member]
Note 4 - Investment Securities Available for Sale (Details) - Securities in a Continuous Loss Position [Line Items]
Securities in continuous unrealized loss position, less than 12 months, fair value	75,985
Securities in continuous unrealized loss position, less than 12 months, unrealized losses	225
Securities in continuous unrealized loss position, fair value	75,985
Securities in continuous unrealized loss position, unrealized losses	225
US States and Political Subdivisions Debt Securities [Member]
Note 4 - Investment Securities Available for Sale (Details) - Securities in a Continuous Loss Position [Line Items]
Securities in continuous unrealized loss position, less than 12 months, fair value	16,353	17,851
Securities in continuous unrealized loss position, less than 12 months, unrealized losses	171	424
Securities in continuous unrealized loss position, 12 months or more, fair value	1,028	945
Securities in continuous unrealized loss position, 12 months or more, unrealized losses	17	54
Securities in continuous unrealized loss position, fair value	17,381	18,796
Securities in continuous unrealized loss position, unrealized losses	188	478
Collateralized Mortgage Backed Securities [Member]
Note 4 - Investment Securities Available for Sale (Details) - Securities in a Continuous Loss Position [Line Items]
Securities in continuous unrealized loss position, less than 12 months, fair value	2,102	27,004
Securities in continuous unrealized loss position, less than 12 months, unrealized losses	14	199
Securities in continuous unrealized loss position, fair value	2,102	27,004
Securities in continuous unrealized loss position, unrealized losses	$ 14	$ 199