Note 1 - Summary of Significant Accounting Policies - Summary of Inventory by Product Group (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Mar. 31, 2025
Prime Coil Inventory [Member]
Raw materials	$ 120,763	$ 85,865
Non-standard Coil Inventory [Member]
Raw materials	31,068	15,737
Tubular Inventory [Member]
Raw materials	9,441	7,055
Finished goods	$ 10,951	$ 5,032

Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480657/210-10-S50-3

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(6)(a)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Name:	us-gaap_InventoryFinishedGoods
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant