Note 4 - Investment Securities Available-for-Sale (Details) - Securities in Continuous Unrealized Loss Position (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Note 4 - Investment Securities Available-for-Sale (Details) - Securities in Continuous Unrealized Loss Position [Line Items]
Less than 12 Months Estimated Fair Value	$ 56,619	$ 210,707
Less than 12 Months Unrealized Losses	242	8,652
12 Months or Greater Estimated Fair Value	98,693	19,019
12 Months or Greater Unrealized Losses	2,435	883
Total Estimated Fair Value	155,312	229,726
Total Unrealized Losses	2,677	9,535
US Government Agencies Debt Securities [Member]
Note 4 - Investment Securities Available-for-Sale (Details) - Securities in Continuous Unrealized Loss Position [Line Items]
Less than 12 Months Estimated Fair Value	2,001	4,782
Less than 12 Months Unrealized Losses	7	148
12 Months or Greater Estimated Fair Value	1,750
12 Months or Greater Unrealized Losses	33
Total Estimated Fair Value	3,751	4,782
Total Unrealized Losses	40	148
Residential Mortgage Backed Securities [Member]
Note 4 - Investment Securities Available-for-Sale (Details) - Securities in Continuous Unrealized Loss Position [Line Items]
Less than 12 Months Estimated Fair Value	49,644	155,475
Less than 12 Months Unrealized Losses	221	5,992
12 Months or Greater Estimated Fair Value	86,028	15,658
12 Months or Greater Unrealized Losses	2,295	683
Total Estimated Fair Value	135,672	171,133
Total Unrealized Losses	2,516	6,675
US States and Political Subdivisions Debt Securities [Member]
Note 4 - Investment Securities Available-for-Sale (Details) - Securities in Continuous Unrealized Loss Position [Line Items]
Less than 12 Months Estimated Fair Value	4,974	50,450
Less than 12 Months Unrealized Losses	14	2,512
12 Months or Greater Estimated Fair Value	10,915	3,196
12 Months or Greater Unrealized Losses	107	188
Total Estimated Fair Value	15,889	53,646
Total Unrealized Losses	121	2,700
Equity Investment Other [Member]
Note 4 - Investment Securities Available-for-Sale (Details) - Securities in Continuous Unrealized Loss Position [Line Items]
12 Months or Greater Estimated Fair Value		165
12 Months or Greater Unrealized Losses		12
Total Estimated Fair Value		165
Total Unrealized Losses		$ 12

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Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

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