Note 12 - Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Net Sales	$ 152,383	$ 106,759	$ 287,160	$ 221,310
Flat-roll [Member]
Net Sales	143,340	97,379	267,407	200,766
Flat-roll [Member] \| Prime Coil [Member]
Net Sales	141,694	96,232	264,540	198,066
Flat-roll [Member] \| Customer Owned [Member]
Net Sales	1,646	1,147	2,867	2,700
Tubular [Member]
Net Sales	9,043	9,380	19,753	20,544
Tubular [Member] \| Manufactured Pipe [Member]
Net Sales	$ 9,043	$ 9,380	$ 19,753	$ 20,544

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.

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+ Details