Note 13 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 6,700,000	$ 5,300,000
Unrecognized Tax Benefits, Interest on Income Taxes Expense	86,200	86,200	$ 129,660
Unrecognized Tax Benefits, Income Tax Penalties Accrued	0
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	389,000	389,000		$ 279,000
Undistributed Earnings of Foreign Subsidiaries	$ 22,900,000	$ 18,900,000
Effective Income Tax Rate Reconciliation, Dividend Received Deduction, Percent	100.00%
State and Local Jurisdiction [Member]
Operating Loss Carryforwards	$ 26,900,000
Deferred Tax Assets, Operating Loss Carryforwards	$ 1,100,000