Note 11 - Segment Information - Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Mar. 31, 2026
Net Sales	$ 239,971	$ 134,777
Cost of Goods and Services Sold	5,753	3,044
Depreciation and amortization	1,069	847
Cost of Product and Service Sold	218,937	127,734
EARNINGS (LOSS) FROM OPERATIONS:	21,034	7,043
Loss on economic hedges of risk	(2,756)	276
Interest expense	(1,224)	(678)
Other expense	(77)	4
EARNINGS BEFORE INCOME TAXES	16,977	6,645
Identifiable assets	373,438		$ 336,810
Material Sold Expense [Member]
Cost of Goods and Services Sold	184,219	105,704
Processing and Warehouse Expense [Member]
Cost of Goods and Services Sold	13,427	9,328
Delivery Expense [Member]
Cost of Goods and Services Sold	9,385	6,400
Commercial Expense [Member]
Cost of Goods and Services Sold	5,084	2,411
Flat-roll [Member]
Net Sales	221,753	124,067
Tubular [Member]
Net Sales	18,218	10,710
Operating Segments [Member]
Identifiable assets	364,210		330,350
Operating Segments [Member] | Flat-roll [Member]
Net Sales	221,753	124,067
Depreciation and amortization	906	769
Cost of Product and Service Sold	197,007	115,281
EARNINGS (LOSS) FROM OPERATIONS:	24,746	8,786
Identifiable assets	329,262		301,528
Operating Segments [Member] | Flat-roll [Member] | Material Sold Expense [Member]
Cost of Goods and Services Sold	171,501	99,154
Operating Segments [Member] | Flat-roll [Member] | Processing and Warehouse Expense [Member]
Cost of Goods and Services Sold	10,717	6,899
Operating Segments [Member] | Flat-roll [Member] | Delivery Expense [Member]
Cost of Goods and Services Sold	9,050	6,260
Operating Segments [Member] | Flat-roll [Member] | Commercial Expense [Member]
Cost of Goods and Services Sold	4,833	2,199
Operating Segments [Member] | Tubular [Member]
Net Sales	18,218	10,710
Depreciation and amortization	81	50
Cost of Product and Service Sold	16,095	9,381
EARNINGS (LOSS) FROM OPERATIONS:	2,123	1,329
Identifiable assets	34,948		28,822
Operating Segments [Member] | Tubular [Member] | Material Sold Expense [Member]
Cost of Goods and Services Sold	12,718	6,550
Operating Segments [Member] | Tubular [Member] | Processing and Warehouse Expense [Member]
Cost of Goods and Services Sold	2,710	2,429
Operating Segments [Member] | Tubular [Member] | Delivery Expense [Member]
Cost of Goods and Services Sold	335	140
Operating Segments [Member] | Tubular [Member] | Commercial Expense [Member]
Cost of Goods and Services Sold	251	212
Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]
Cost of Goods and Services Sold	5,753	3,044
Depreciation and amortization	82	28
Cost of Product and Service Sold	5,835	3,072
EARNINGS (LOSS) FROM OPERATIONS:	(5,835)	$ (3,072)
Identifiable assets	$ 9,228		$ 6,460