Note 10 - Income Taxes (Details) - A Reconciliation of Income Tax Expense	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
A Reconciliation of Income Tax Expense [Abstract]
Computed at statutory rate	34.00%	34.00%	34.00%
Increase (reduction) in taxes resulting from:
State financial institution tax and credits	(4.80%)	(4.80%)	(4.80%)
Cash surrender value of life insurance	(1.50%)	(1.60%)	(2.00%)
Other	2.40%	(0.80%)	5.20%
Actual effective rate	30.10%	26.80%	32.40%