Note 19 - Revenue From Contracts With Customers (Details Textual) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Trading Activity Charges Reducing Product Sales Commissions and Fees	$ 417,000	$ 391,000
Contract with Customer, Asset, after Allowance for Credit Loss, Total	0
Contract with Customer, Liability, Total	0
Fiduciary and Trust [Member]
Accrued Fees and Other Revenue Receivable	$ 2,100,000		$ 2,100,000