Note 8 - Income Taxes (Details Textual) - USD ($)	3 Months Ended			9 Months Ended		12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Income Tax Expense (Benefit), Total	$ 1,261,000	$ 2,100,000		$ 4,603,000	$ 6,576,000
Effective Income Tax Rate Reconciliation, Percent, Total	22.90%	21.60%		23.40%	21.70%
Tax Adjustments, Settlements, and Unusual Provisions	$ 29,000
Proceeds from Income Tax Refunds					$ 285,000	$ 194,000
Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), Share-based Payment Arrangement, Amount			$ 106,000