Note 9 - Derivative Financial Instruments - Gain (Loss) Recognized in Earnings for Derivative Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Hot-rolled coil steel contracts			$ 500	$ 1,629
Hot-rolled Coil Future Contracts [Member] | Designated as Hedging Instrument [Member]
Hot-rolled coil steel contracts	$ 851	$ 194		$ 5,569
Hot-rolled Coil Steel Contracts [Member] | Nonoperating Income (Expense) [Member]
Hot-rolled coil steel contracts			$ 1,127