Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 28, 2026	Feb. 28, 2025	Feb. 28, 2026	Feb. 28, 2025
Statement of Comprehensive Income [Abstract]
Net earnings attributable to controlling interest	$ 10.4	$ 13.8	$ 66.0	$ 55.0
Net earnings (loss) attributable to noncontrolling interests	0.4	(1.7)	4.9	5.4
Net earnings	10.8	12.1	70.9	60.4
Other comprehensive income, net of tax
Foreign currency translation, net	3.8	(3.7)	5.5	(6.4)
Net investment hedge	(1.0)	0.0	(1.6)	0.0
Pension liability adjustment	0.0	0.0	0.0	(1.0)
Cash flow hedges	0.8	(1.9)	2.2	(1.9)
Other comprehensive income (loss)	3.6	(5.6)	6.1	(9.3)
Comprehensive income	14.4	6.5	77.0	51.1
Comprehensive income (loss) attributable to noncontrolling interests	0.4	(1.7)	4.9	5.4
Comprehensive income attributable to Worthington Steel	$ 14.0	$ 8.2	$ 72.1	$ 45.7