Accumulated Other Comprehensive Income (Loss) - Schedule of AOCI Activity (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2022	Nov. 30, 2021	Nov. 30, 2022	Nov. 30, 2021
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			$ (45.4)
Other comprehensive income (loss) before reclassifications	$ 3.0	$ (3.9)	(6.6)	$ (9.7)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax	(0.1)	(0.2)	(0.2)	(0.4)
Amortization of prior service (credit) cost (net of tax of $0.0)	(0.2)	(0.2)	(0.3)	(0.3)
Other comprehensive income (loss)	2.9	(3.9)	(6.7)	(9.6)
Ending balance	(52.1)	(44.3)	(52.1)	(44.3)
Other Comprehensive Income (Loss) before Reclassifications, Tax		(0.1)		(0.1)
Amortization of prior service credit, tax	0.0	0.0	0.1
Reclassification adjustment from AOCI, tax	0.0	0.0	0.0	0.0
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(55.0)	(40.4)	(45.4)	(34.7)
Ending balance	(52.1)	(44.3)	(52.1)	(44.3)
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(54.2)	(35.9)	(44.6)	(30.1)
Other comprehensive income (loss) before reclassifications	3.0	(4.4)	(6.6)	(10.2)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax	0.0	0.0	0.0	0.0
Amortization of prior service (credit) cost (net of tax of $0.0)	0.0	0.0	0.0	0.0
Other comprehensive income (loss)	3.0	(4.4)	(6.6)	(10.2)
Ending balance	(51.2)	(40.3)	(51.2)	(40.3)
Retirement benefit plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(0.8)	(4.5)	(0.8)	(4.6)
Other comprehensive income (loss) before reclassifications	0.0	0.5	0.0	0.5
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax	(0.1)	(0.2)	(0.2)	(0.4)
Amortization of prior service (credit) cost (net of tax of $0.0)	(0.2)	(0.2)	(0.3)	(0.3)
Other comprehensive income (loss)	(0.1)	0.5	(0.1)	0.6
Ending balance	$ (0.9)	$ (4.0)	$ (0.9)	$ (4.0)