Note 11 - Subsequent Events (Details Textual) - $ / shares		12 Months Ended
	May 04, 2022	Mar. 31, 2022	Mar. 31, 2021
Common Stock, Dividends, Per Share, Declared (in dollars per share)		$ 4.00	$ 4.00
Subsequent Event [Member]
Common Stock, Dividends, Per Share, Declared (in dollars per share)	$ 1.00
Dividends Payable, Date to be Paid	May 31, 2022
Dividends Payable, Date of Record	May 16, 2022