Note 8 - Income Taxes (Details Textual) - USD ($)	3 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Income Tax Expense (Benefit), Total	$ 2,013,000	$ 1,642,000
Effective Income Tax Rate Reconciliation, Percent, Total	20.60%	23.50%
Proceeds from Income Tax Refunds	$ 285,000