Note 8 - Derivative Financial Instruments - Gain (Loss) Recognized in Earnings for Derivative Instruments (Details) - USD ($) $ in Thousands	3 Months Ended
Jun. 30, 2025	Jun. 30, 2024
Hot-rolled coil steel contracts	$ (103)	$ 1,608
Hot-rolled Coil Future Contracts [Member] \| Designated as Hedging Instrument [Member]
Hot-rolled coil steel contracts	$ 276
Hot-rolled Coil Steel Contracts [Member] \| Nonoperating Income (Expense) [Member]
Hot-rolled coil steel contracts		$ 5,375

Amount, before tax and reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 182
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4A
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4A

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
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-Publisher FASB
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
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