Employee Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Employee benefit plans
Pension expense	$ 7.3	$ 4.0	$ 11.6
Net Periodic Benefit Cost
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)
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)	Other Nonoperating Income (Expense)
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)
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	$ 0.5
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	159.0	$ 159.1
Service cost	1.5		$ 2.5
Interest cost	3.1	3.1
Participant contributions	0.1	0.3
Net actuarial (gain) loss	(25.0)	(4.4)
Benefits and administrative payments	(5.1)	(4.8)
Settlements	(2.5)	(2.0)
Curtailment	(2.0)	(2.5)
Foreign currency translation adjustment	(8.9)	7.7
Projected benefit obligation at end of year	120.2	159.0	159.1
Change in the fair value of plan assets:
Fair value of plan assets at beginning of year	158.4	131.8
Actual return on plan assets	(16.7)		23.8
Employer contributions	0.5	2.7
Participant contributions	0.1	0.3
Benefits and administrative payments, including settlements	(7.6)	(6.8)
Foreign currency translation adjustment	(8.5)	6.6
Fair value of plan assets at end of year	126.2	158.4	131.8
Funded status at end of year	6.0	(0.6)
Accumulated other comprehensive loss	30.9	37.8
Amounts recognized in the Consolidated Balance Sheets
Other non-current assets	9.7	10.4
Accrued liabilities	(0.3)	(0.4)
Other liabilities	(3.4)	(10.6)
Funded status at end of year	6.0	(0.6)
Accumulated benefit obligation in excess of plan assets
Accumulated benefit obligation	116.5	153.0
Net Periodic Benefit Cost
Service cost	1.5	2.5	2.8
Interest cost	3.1	3.1	3.8
Expected return on plan assets	(7.5)	(6.6)	(6.8)
Settlements	1.4	0.9	1.5
Recognized net actuarial loss	1.5	2.3	2.0
Total		2.2	3.3
Defined Benefit Pension Plans | Benefit obligation in excess of plan assets
Projected benefit obligation in excess of plan assets
Projected benefit obligation	3.7	88.1
Fair value of plan assets		77.1
Accumulated benefit obligation in excess of plan assets
Projected benefit obligation	3.7	88.1
Fair value of plan assets		77.1
Accumulated benefit obligation	3.7	82.1
Merged U.S. Plan
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	70.9	75.4
Service cost	0.3		0.3
Interest cost	2.0	2.1
Net actuarial (gain) loss	(7.6)	(1.9)
Benefits and administrative payments	(3.0)	(3.0)
Settlements	(2.5)	(2.0)
Projected benefit obligation at end of year	60.1	70.9	75.4
Change in the fair value of plan assets:
Fair value of plan assets at beginning of year	81.3	65.4
Actual return on plan assets	(6.8)		20.9
Benefits and administrative payments, including settlements	(5.5)	(5.0)
Fair value of plan assets at end of year	69.0	81.3	65.4
Funded status at end of year	8.9	10.4
Accumulated other comprehensive loss	26.2	24.7
Net Periodic Benefit Cost
Service cost	0.3	0.3	0.6
Interest cost	2.0	2.1	2.6
Expected return on plan assets	(5.0)	(4.8)	(4.9)
Settlements	1.4	0.9	1.5
Recognized net actuarial loss	1.2	1.5	1.2
Total	$ (0.1)		1.0
Merged U.S. Plan | Minimum
Employee benefit plans
Expected period to terminate the benefit plan	12 months
Merged U.S. Plan | Maximum
Employee benefit plans
Expected period to terminate the benefit plan	18 months
Other U.S. Plans
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	$ 4.4	4.6
Interest cost	0.1	0.1
Net actuarial (gain) loss	(0.4)	0.1
Benefits and administrative payments	(0.4)	(0.4)
Projected benefit obligation at end of year	3.7	4.4	4.6
Change in the fair value of plan assets:
Employer contributions	0.4	0.4
Benefits and administrative payments, including settlements	(0.4)	(0.4)
Funded status at end of year	(3.7)	(4.4)
Accumulated other comprehensive loss	0.7	1.3
Net Periodic Benefit Cost
Interest cost	0.1	0.1	0.1
Recognized net actuarial loss	0.1	0.1	0.1
Total	$ 0.2	$ 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)	2.96%	2.87%
Weighted-average assumptions used to determine net periodic pension expense
Discount rate: (as a percent)	2.87%	2.83%	3.67%
Expected long-term rate on plan assets: (as a percent)	7.25%	7.25%	7.25%
Netherlands Plan
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	$ 83.7	$ 79.1
Service cost	1.2		$ 2.2
Interest cost	1.0	0.9
Participant contributions	0.1	0.3
Net actuarial (gain) loss	(17.0)	(2.6)
Benefits and administrative payments	(1.7)	(1.4)
Curtailment	(2.0)	(2.5)
Foreign currency translation adjustment	(8.9)	7.7
Projected benefit obligation at end of year	56.4	83.7	79.1
Change in the fair value of plan assets:
Fair value of plan assets at beginning of year	77.1	66.4
Actual return on plan assets	(9.9)		2.9
Employer contributions	0.1	2.3
Participant contributions	0.1	0.3
Benefits and administrative payments, including settlements	(1.7)	(1.4)
Foreign currency translation adjustment	(8.5)	6.6
Fair value of plan assets at end of year	57.2	77.1	66.4
Funded status at end of year	0.8	(6.6)
Accumulated other comprehensive loss	3.9	11.8
Net Periodic Benefit Cost
Service cost	1.2	2.2	2.2
Interest cost	1.0	0.9	1.1
Expected return on plan assets	(2.5)	(1.8)	(1.9)
Recognized net actuarial loss	0.2	0.7	0.7
Total	$ (0.1)	$ 2.0	$ 2.1
Key weighted-average assumptions used in the measurement of the company's projected benefit obligations
Discount rate (as a percent)	2.80%	1.20%
Weighted-average assumptions used to determine net periodic pension expense
Discount rate: (as a percent)	1.20%	1.20%	1.50%
Expected long-term rate on plan assets: (as a percent)	3.30%	2.50%	2.90%