Note 7 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2020
Effective Income Tax Rate Reconciliation, Percent, Total	4.80%	4.10%	4.40%	3.40%
Deferred Income Tax Expense (Benefit), Total	$ 700	$ 900	$ 1,400	$ 1,500
Current Income Tax Expense (Benefit), Total	$ 10	$ 20	$ 30	$ 30
Forecast [Member]
Effective Income Tax Rate Reconciliation, Percent, Total					2.30%