Note 21 - Income Taxes - Reconciliation of Income Taxes (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income tax at the federal statutory rate	21.00%	34.00%	34.00%
Deferred tax asset write-down		17.50%	5.00%
State franchise tax, net of federal tax benefit	8.30%	6.50%	6.10%
Amortization of affordable housing credit partnerships	2.70%	4.80%	8.10%
Officer life insurance	(0.60%)	(2.50%)	(2.90%)
Tax-exempt interest	(1.80%)	(5.20%)	(10.90%)
Affordable housing credits and benefits	(3.80%)	(5.70%)	(11.70%)
Accelerated depreciation - cost segregation study	(2.50%)
Reversal of uncertain tax position	(5.10%)
Other	0.50%	(0.80%)	(0.70%)
Effective Tax Rate	18.70%	48.50%	27.10%