Note 7 - Indebtedness - Interest Expense on the Notes (Details) - The Notes [Member] - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021
Coupon interest expense at 1.375%	$ 593	$ 593	$ 1,779	$ 1,779
Amortization of debt discounts and issuance costs	227	223	679	666
Total interest and amortization of debt issuance costs	$ 820	$ 816	$ 2,458	$ 2,445

Amount of amortization expense attributable to debt discount (premium) and debt issuance costs.

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