Operating Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Nov. 30, 2024	Nov. 30, 2023	Nov. 30, 2024	Nov. 30, 2023	Feb. 29, 2024
Operations and assets by segment
Sales	$ 403,654	$ 381,605	$ 1,225,869	$ 1,171,020
Cost of sales	305,876	293,456	921,907	888,606
Gross margin	97,778	88,149	303,962	282,414
Selling, general and administrative	39,243	35,325	108,032	103,087
Operating income (loss)	58,535	52,824	195,930	179,327
Interest expense, net	(19,223)	(25,855)	(63,906)	(82,331)
Equity in earnings of unconsolidated subsidiaries	7,168	8,742	12,470	11,136
Other income (expense)	(763)	(41)	(142)	9
Income (loss) before income tax	45,717	35,670	144,352	108,141
Income taxes	12,114	8,780	35,728	24,397
Net income from continuing operations	33,603	26,890	108,624	83,744
Assets:	2,244,550		2,244,550		$ 2,195,505
Property, plant and equipment, net	$ 580,178		$ 580,178		541,652
AIS Joint Venture
Operations and assets by segment
Ownership percentage of investment	40.00%		40.00%
United States
Operations and assets by segment
Sales	$ 392,503	370,485	$ 1,194,212	1,140,344
Property, plant and equipment, net	561,326		561,326		522,693
Canada
Operations and assets by segment
Sales	11,151	11,120	31,657	30,676
Property, plant and equipment, net	18,852		18,852		18,959
Corporate
Operations and assets by segment
Sales	0	0	0	0
Cost of sales	0	0	0	0
Gross margin	0	0	0	0
Selling, general and administrative	24,889	17,480	65,699	52,271
Operating income (loss)	(24,889)	(17,480)	(65,699)	(52,271)
Interest expense, net	(19,223)	(25,855)	(63,906)	(82,331)
Equity in earnings of unconsolidated subsidiaries	0	0	0	0
Other income (expense)	(879)	(12)	(307)	49
Income (loss) before income tax	(44,991)	(43,347)	(129,912)	(134,553)
Income taxes	12,114	8,780	35,728	24,397
Net income from continuing operations	(57,105)	(52,127)	(165,640)	(158,950)
Assets:	31,788		31,788		43,709
Metal Coatings | Operating Segments
Operations and assets by segment
Sales	168,599	163,186	516,750	501,816
Cost of sales	116,542	115,952	357,471	353,280
Gross margin	52,057	47,234	159,279	148,536
Selling, general and administrative	5,684	9,392	17,286	20,143
Operating income (loss)	46,373	37,842	141,993	128,393
Interest expense, net	0	0	0	0
Equity in earnings of unconsolidated subsidiaries	0	0	0	0
Other income (expense)	116	(29)	165	(40)
Income (loss) before income tax	46,489	37,813	142,158	128,353
Assets:	551,379		551,379		553,505
Precoat Metals | Operating Segments
Operations and assets by segment
Sales	235,055	218,419	709,119	669,204
Cost of sales	189,334	177,504	564,436	535,326
Gross margin	45,721	40,915	144,683	133,878
Selling, general and administrative	8,641	8,163	24,980	24,429
Operating income (loss)	37,080	32,752	119,703	109,449
Interest expense, net	0	0	0	0
Equity in earnings of unconsolidated subsidiaries	0	0	0	0
Other income (expense)	0	0	0	0
Income (loss) before income tax	37,080	32,752	119,703	109,449
Assets:	1,559,262		1,559,262		1,500,122
Infrastructure Solutions | Operating Segments
Operations and assets by segment
Sales	0	0	0	0
Cost of sales	0	0	0	0
Gross margin	0	0	0	0
Selling, general and administrative	29	290	67	6,244
Operating income (loss)	(29)	(290)	(67)	(6,244)
Interest expense, net	0	0	0	0
Equity in earnings of unconsolidated subsidiaries	7,168	8,742	12,470	11,136
Other income (expense)	0	0	0	0
Income (loss) before income tax	7,139	$ 8,452	12,403	$ 4,892
Assets:	$ 102,121		$ 102,121		$ 98,169