CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Millions	Common Stock	Capital Surplus	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss	Total
Balance at May. 31, 2021	$ 45.3	$ 479.8	$ 741.7	$ (274.1)	$ (18.3)	$ 974.4
Increase (Decrease) in Stockholders' Equity
Net income			78.7			78.7
Stock option activity		2.0		19.3		21.3
Restricted stock activity		(4.3)		8.1		3.8
Repurchase of shares				(42.4)		(42.4)
Other comprehensive income, net of tax					(1.3)	(1.3)
Balance at May. 31, 2022	45.3	477.5	820.4	(289.1)	(19.6)	1,034.5
Increase (Decrease) in Stockholders' Equity
Net income			90.2			90.2
Stock option activity		0.3		19.2		19.5
Restricted stock activity		6.7		2.2		8.9
Repurchase of shares				(50.1)		(50.1)
Other comprehensive income, net of tax					(3.9)	(3.9)
Balance at May. 31, 2023	45.3	484.5	910.6	(317.8)	(23.5)	1,099.1
Increase (Decrease) in Stockholders' Equity
Net income	0.0	0.0	46.3	0.0	0.0	46.3
Stock option activity		2.9		21.7		24.6
Restricted stock activity		6.5		3.7		10.2
Repurchase of shares				(5.1)		(5.1)
Other comprehensive income, net of tax					14.7	14.7
Balance at May. 31, 2024	$ 45.3	$ 493.9	$ 956.9	$ (297.5)	$ (8.8)	$ 1,189.8