Employee Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2023	May 31, 2022	May 31, 2021
Employee benefit plans
Pension expense	$ 7.5	$ 7.3	$ 4.0
Net Periodic Benefit Cost
Service cost	0.5
Interest cost	$ 3.3
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Expected return on plan assets	$ (4.1)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Settlement Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]		Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Recognized net actuarial loss	$ 0.8
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Total	$ 0.5
Cash balance pension plan
Employee benefit plans
Interest crediting rate as a percentage of average 30-year treasury rate	100.00%
Average period of treasury rate used in determination of interest crediting rate	30 years
Average interest crediting rate (as a percent)	4.46%
Defined Benefit Pension Plans
Employee benefit plans
Pension expense	$ 1.2	$ 0.5
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	120.2	159.0
Service cost	0.5	1.5
Interest cost	3.3	3.1
Participant contributions		0.1
Net actuarial gain	(9.5)	(25.0)
Benefits and administrative payments	(5.8)	(5.1)
Settlements		(2.5)
Curtailment		(2.0)
Foreign currency translation adjustment	(0.7)	(8.9)
Projected benefit obligation at end of year	108.0	120.2	$ 159.0
Change in the fair value of plan assets:
Fair value of plan assets at beginning of year	126.2	158.4
Actual return on plan assets	(7.4)	(16.7)
Employer contributions	0.3	0.5
Participant contributions		0.1
Benefits and administrative payments	(5.8)	(7.6)
Foreign currency translation adjustment	(0.7)	(8.5)
Fair value of plan assets at end of year	112.6	126.2	158.4
Funded status at end of year	4.6	6.0
Accumulated other comprehensive loss	32.1	30.9
Amounts recognized in the Consolidated Balance Sheets
Other non-current assets	8.7	9.7
Accrued liabilities	(0.2)	(0.3)
Other liabilities	(3.9)	(3.4)
Funded status at end of year	4.6	6.0
Accumulated benefit obligation in excess of plan assets
Accumulated benefit obligation	105.3	116.5
Net Periodic Benefit Cost
Service cost		1.5	2.5
Interest cost		3.1	3.1
Expected return on plan assets		(7.5)	(6.6)
Settlements		1.4	0.9
Recognized net actuarial loss		1.5	2.3
Total			2.2
Defined Benefit Pension Plans | Benefit obligation in excess of plan assets
Projected benefit obligation in excess of plan assets
Projected benefit obligation	54.3	3.7
Fair value of plan assets	50.2
Accumulated benefit obligation in excess of plan assets
Projected benefit obligation	54.3	3.7
Fair value of plan assets	50.2
Accumulated benefit obligation	51.6	3.7
Merged U.S. Plan
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	60.1	70.9
Service cost	0.3	0.3
Interest cost	1.7	2.0
Net actuarial gain	(4.4)	(7.6)
Benefits and administrative payments	(4.0)	(3.0)
Settlements		(2.5)
Projected benefit obligation at end of year	53.7	60.1	70.9
Change in the fair value of plan assets:
Fair value of plan assets at beginning of year	69.0	81.3
Actual return on plan assets	(2.6)	(6.8)
Benefits and administrative payments	(4.0)	(5.5)
Fair value of plan assets at end of year	62.4	69.0	81.3
Funded status at end of year	8.7	8.9
Accumulated other comprehensive loss	25.7	26.2
Net Periodic Benefit Cost
Service cost	0.3	0.3	0.3
Interest cost	1.7	2.0	2.1
Expected return on plan assets	(2.0)	(5.0)	(4.8)
Settlements		1.4	0.9
Recognized net actuarial loss	0.8	1.2	1.5
Total	0.8	(0.1)
Other U.S. Plans
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	3.7	4.4
Interest cost	0.1	0.1
Net actuarial gain	(0.5)	(0.4)
Benefits and administrative payments	(0.3)	(0.4)
Projected benefit obligation at end of year	3.0	3.7	4.4
Change in the fair value of plan assets:
Employer contributions	0.3	0.4
Benefits and administrative payments	(0.3)	(0.4)
Funded status at end of year	(3.0)	(3.7)
Accumulated other comprehensive loss	0.1	0.7
Net Periodic Benefit Cost
Interest cost	0.1	0.1	0.1
Recognized net actuarial loss		0.1	0.1
Total	$ 0.1	$ 0.2	$ 0.2
U.S. plans
Key weighted-average assumptions used in the measurement of the company's projected benefit obligations
Discount rate (as a percent)	5.59%	2.96%
Weighted-average assumptions used to determine net periodic pension expense
Discount rate: (as a percent)	2.96%	2.87%	2.83%
Expected long-term rate on plan assets: (as a percent)	2.91%	7.25%	7.25%
Netherlands Plan
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	$ 56.4	$ 83.7
Service cost	0.2	1.2
Interest cost	1.5	1.0
Participant contributions		0.1
Net actuarial gain	(4.6)	(17.0)
Benefits and administrative payments	(1.5)	(1.7)
Curtailment		(2.0)
Foreign currency translation adjustment	(0.7)	(8.9)
Projected benefit obligation at end of year	51.3	56.4	$ 83.7
Change in the fair value of plan assets:
Fair value of plan assets at beginning of year	57.2	77.1
Actual return on plan assets	(4.8)	(9.9)
Employer contributions		0.1
Participant contributions		0.1
Benefits and administrative payments	(1.5)	(1.7)
Foreign currency translation adjustment	(0.7)	(8.5)
Fair value of plan assets at end of year	50.2	57.2	77.1
Funded status at end of year	(1.1)	0.8
Accumulated other comprehensive loss	6.3	3.9
Net Periodic Benefit Cost
Service cost	0.2	1.2	2.2
Interest cost	1.5	1.0	0.9
Expected return on plan assets	(2.1)	(2.5)	(1.8)
Recognized net actuarial loss		0.2	0.7
Total	$ (0.4)	$ (0.1)	$ 2.0
Key weighted-average assumptions used in the measurement of the company's projected benefit obligations
Discount rate (as a percent)	3.70%	2.80%
Weighted-average assumptions used to determine net periodic pension expense
Discount rate: (as a percent)	2.80%	1.20%	1.20%
Expected long-term rate on plan assets: (as a percent)	3.90%	3.30%	2.50%