Operating Segments (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Feb. 28, 2025	Feb. 28, 2025	Feb. 29, 2024	Feb. 28, 2023
Operations and assets by segment
Sales		$ 1,577,744	$ 1,537,589	$ 1,323,649
Cost of sales		1,195,064	1,174,128	1,027,706
Cost, Depreciation			1,174,128	1,027,706
Gross margin		382,680	363,461	295,943
Selling, general and administrative		146,316	141,861	122,305
Operating income (loss)		236,364	221,600	173,638
Interest expense, net		(81,282)	(107,065)	(88,800)
Equity in earnings of unconsolidated subsidiaries		16,163	15,407	2,597
Other income (expense)		(562)	161	1,240
Income (loss) before income tax		170,683	130,103	88,675
Income taxes		41,850	28,496	22,336
Net income from continuing operations		128,833	101,607	66,339
Payments To Acquire Property, Plant, Equipment And Acquire Businesses, Net Of Cash		115,883	95,119	1,339,850
Assets:	$ 2,227,101	2,227,101	2,195,505
Property, plant and equipment, net	592,941	592,941	541,652
Amortization of intangible assets		23,111	23,960	22,613
Legal matter expense	500
Legal settlement and accrual related to non-operating entity		3,500
Legal settlement from acquisition			5,800
Depreciation		82,205	79,423	74,590
Cost of sales
Operations and assets by segment
Amortization of intangible assets		0	0	7,124
Selling, general and administrative
Operations and assets by segment
Amortization of intangible assets		23,111	23,960	15,489
AIS Joint Venture
Operations and assets by segment
Equity in earnings of unconsolidated subsidiaries		16,200	15,400	2,600
United States
Operations and assets by segment
Sales		1,537,215	1,498,397	1,279,890
Property, plant and equipment, net	574,332	574,332	522,693
Canada
Operations and assets by segment
Sales		40,529	39,192	43,759
Property, plant and equipment, net	18,609	18,609	18,959
Corporate
Operations and assets by segment
Sales		0	0	0
Cost of sales		0
Cost, Depreciation			0	0
Gross margin		0	0	0
Selling, general and administrative		83,202	76,453	61,824
Operating income (loss)		(83,202)	(76,453)	(61,824)
Interest expense, net		(81,282)	(107,065)	(88,800)
Equity in earnings of unconsolidated subsidiaries		0	0	0
Other income (expense)		(809)	33	374
Income (loss) before income tax		(165,293)	(183,485)	(150,250)
Income taxes		41,850	28,496	22,336
Net income from continuing operations		(207,143)	(211,981)	(172,586)
Payments To Acquire Property, Plant, Equipment And Acquire Businesses, Net Of Cash		1,388	1,826	797
Assets:	24,250	24,250	43,709
Amortization of intangible assets			24,000
Severance costs		3,700
Depreciation		24,380	25,130	1,436
Corporate | Selling, general and administrative
Operations and assets by segment
Amortization of intangible assets		23,100
Metal Coatings
Operations and assets by segment
Legal matter expense			5,500
Metal Coatings | Cost of sales
Operations and assets by segment
Amortization of intangible assets				7,100
Metal Coatings | Operating Segments
Operations and assets by segment
Sales		665,107	656,189	636,982
Cost of sales		464,260
Cost, Depreciation			465,147	462,473
Gross margin		200,847	191,042	174,509
Selling, general and administrative		22,372	26,314	18,556
Operating income (loss)		178,475	164,728	155,953
Interest expense, net		0	0	0
Equity in earnings of unconsolidated subsidiaries		0	0	0
Other income (expense)		247	128	101
Income (loss) before income tax		178,722	164,856	156,054
Payments To Acquire Property, Plant, Equipment And Acquire Businesses, Net Of Cash		29,958	25,484	23,639
Assets:	555,095	555,095	553,505
Depreciation		26,640	26,353	32,955
Precoat Metals
Operations and assets by segment
Legal matter expense		6,500	5,800
Precoat Metals | Cost of sales
Operations and assets by segment
Amortization of intangible assets				15,500
Precoat Metals | Operating Segments
Operations and assets by segment
Sales		912,637	881,400	686,667
Cost of sales		730,804
Cost, Depreciation			708,981	565,233
Gross margin		181,833	172,419	121,434
Selling, general and administrative		34,005	32,848	41,925
Operating income (loss)		147,828	139,571	79,509
Interest expense, net		0	0	0
Equity in earnings of unconsolidated subsidiaries		0	0	0
Other income (expense)		0	0	765
Income (loss) before income tax		147,828	139,571	80,274
Payments To Acquire Property, Plant, Equipment And Acquire Businesses, Net Of Cash		84,537	67,809	1,315,414
Assets:	1,548,377	1,548,377	1,500,122
Depreciation		31,185	27,940	40,199
Infrastructure Solutions | Operating Segments
Operations and assets by segment
Sales		0	0	0
Cost of sales		0
Cost, Depreciation			0	0
Gross margin		0	0	0
Selling, general and administrative		6,737	6,246	0
Operating income (loss)		(6,737)	(6,246)	0
Interest expense, net		0	0	0
Equity in earnings of unconsolidated subsidiaries		16,163	15,407	2,597
Other income (expense)		0	0	0
Income (loss) before income tax		9,426	9,161	$ 2,597
Assets:	$ 99,379	$ 99,379	$ 98,169