Note 9 - Borrowed Funds - Repurchase Agreements Collateralized by Mortgage-backed Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Book value of collateral	$ 0	$ 131,421	$ 142,925
Estimated fair value of collateral	0	131,421	142,925
Average balance of outstanding agreements during the year	64,087	116,000	137,824
Maximum balance of outstanding agreements at a month end during the year	$ 116,000	$ 116,000	$ 155,300
Average interest rate of outstanding agreements during the year	3.26%	3.22%	3.40%