Note 8 - Loans - Troubled Debt Restructuring Activity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Charge-offs	$ 0	$ 0
Accruing Troubled Debt Restructuring [Member]
Beginning balance	35,336	65,071
New restructurings	534	1,948
Payments	(1,506)	(4,071)
Ending balance	34,364	62,948
Non-accruing Troubled Debt Restructuring [Member]
Beginning balance	18,048	24,189
Payments	(159)	(481)
Charge-offs	0	(407)
Ending balance	$ 17,889	$ 23,301