Note 3 - Income Taxes (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Effective Income Tax Rate Reconciliation, Percent, Total	17.90%	17.20%	8.10%	18.70%
Deferred Tax Liabilities, Employer Social Security Tax Break Under CARES Act	$ 800,000		$ 800,000