Note 13 - Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Revenue from Contract with Customer, Including Assessed Tax	$ 646,913	$ 444,600
Flat-roll [Member] \| Prime Coil [Member]
Revenue from Contract with Customer, Including Assessed Tax	590,956	399,853
Flat-roll [Member] \| Customer Owned [Member]
Revenue from Contract with Customer, Including Assessed Tax	5,174	4,791
Tubular [Member] \| Manufactured Pipe [Member]
Revenue from Contract with Customer, Including Assessed Tax	$ 50,783	$ 39,956

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details