Note 7 - Changes in Shareholders' Equity (Details Textual) - USD ($) shares in Thousands, $ in Millions	9 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Stock Repurchased and Retired During Period, Shares (in shares)	0	0
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 28.7

Number of shares that have been repurchased and retired during the period.

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration