Consolidated Statements of Earnings - USD ($) $ in Millions	3 Months Ended
	Aug. 31, 2025	Aug. 31, 2024	May 31, 2025
Income Statement [Abstract]
Net sales	$ 872.9	$ 834.0
Cost of goods sold	757.7	733.6
Gross margin	115.2	100.4
Selling, general and administrative expense	67.9	57.0
Restructuring and other (income), net	(1.0)	0.0
Operating income	48.3	43.4
Other income (expense):
Miscellaneous income (expense), net	0.2	(5.9)
Interest expense, net	(2.9)	(2.6)
Equity in net income of unconsolidated affiliate	6.4	1.3
Earnings before income taxes	52.0	36.2
Income tax expense	13.4	4.0
Net earnings	38.6	32.2
Net earnings attributable to noncontrolling interests	1.8	3.8
Net earnings attributable to Worthington Steel	36.8	28.4
Deemed dividend of redeemable noncontrolling interest	0.5	0.0
Net earnings attributable to Worthington Steel shareholders	$ 36.3	$ 28.4
Basic
Weighted average common shares outstanding	49,600,000	49,400,000
Earnings per share attributable to Worthington Steel shareholders	$ 0.73	$ 0.57
Diluted
Weighted average common shares outstanding	50,600,000	50,400,000
Earnings per share attributable to Worthington Steel shareholders	$ 0.72	$ 0.56
Common shares outstanding at end of period	49,635,244	49,400,000	49,548,895
Cash dividends declared per share	$ 0.16	$ 0.16