Note 10 - Retirement Plans - Amounts Recognized in Accumulated Other Comprehensive (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Prior service cost	$ (9)	$ (75)	$ (167)
Net loss	(34,883)	(28,310)	(36,136)
Accumulated other comprehensive pre-tax loss	$ (34,892)	$ (28,385)	$ (36,303)

Amount, before tax, of accumulated other comprehensive (income) loss for defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

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Name:	us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant