Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Aug. 31, 2023	Aug. 31, 2022
Accumulated Other Comprehensive Loss
Balance at June 1, 2023	$ (23.5)	$ (19.6)
Other comprehensive income (loss) before reclassifications	0.5	(3.3)
Amounts reclassified from AOCL	14.9	0.2
Total other comprehensive income (loss)	15.4	(3.1)
Balance at August 31, 2023	(8.1)	(22.7)
Currency Translation Adjustments
Accumulated Other Comprehensive Loss
Balance at June 1, 2023	(5.7)	(2.8)
Other comprehensive income (loss) before reclassifications	0.5	(3.3)
Total other comprehensive income (loss)	0.5	(3.3)
Balance at August 31, 2023	(5.2)	(6.1)
Pensions Plans
Accumulated Other Comprehensive Loss
Balance at June 1, 2023	(17.8)	(16.8)
Amounts reclassified from AOCL	14.9	0.2
Total other comprehensive income (loss)	14.9	0.2
Balance at August 31, 2023	$ (2.9)	$ (16.6)