Employee Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2021	May 31, 2020	May 31, 2019
Estimated amounts that will be amortized from accumulated other comprehensive loss into expense over the next fiscal year
Estimated amount of net actuarial loss	$ 1.6
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
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	$ 159.1	$ 149.2
Service cost	2.5	2.8
Interest cost	3.1	3.8
Participant contributions	0.3	0.3
Net actuarial (gain) loss	(4.4)	10.1
Benefits and administrative payments	(4.8)	(4.9)
Settlements	(2.0)	(2.2)
Curtailment	(2.5)
Foreign currency translation adjustment	7.7
Projected benefit obligation at end of year	159.0	159.1	$ 149.2
Change in the fair value of plan assets:
Fair value of plan assets at beginning of year	131.8	129.9
Actual return on plan assets	23.8	8.6
Employer contributions	2.7	0.4
Participant contributions	0.3	0.3
Benefits and administrative payments, including settlements	(6.8)	(7.1)
Foreign currency translation adjustment	6.6
Fair value of plan assets at end of year	158.4	131.8	129.9
Funded status at end of year	(0.6)	(27.3)
Amounts recognized in the Consolidated Balance Sheets
Other non-current assets	(10.4)
Accrued liabilities	(0.4)	(0.4)
Other liabilities	(10.6)	(26.9)
Funded status at end of year	(0.6)	(27.3)
Accumulated other comprehensive loss	37.8	63.5
Accumulated benefit obligation in excess of plan assets
Accumulated benefit obligation	153.0	151.9
Net Periodic Benefit Cost
Service cost	2.5	2.8	2.3
Interest cost	3.1	3.8	4.3
Expected return on plan assets	(6.6)	(6.8)	(7.1)
Settlements	0.9	1.5	0.1
Amortization of prior service credit			(0.1)
Recognized net actuarial loss	2.3	2.0	1.8
Total	2.2	3.3	$ 1.3
Defined Benefit Pension Plans | Benefit obligation in excess of plan assets
Projected benefit obligation in excess of plan assets
Projected benefit obligation	88.1	159.1
Fair value of plan assets	77.1	131.8
Accumulated benefit obligation in excess of plan assets
Projected benefit obligation	88.1	159.1
Fair value of plan assets	77.1	131.8
Accumulated benefit obligation	$ 82.1	$ 83.4
Domestic plans
Key weighted-average assumptions used in the measurement of the company's projected benefit obligations
Discount rate (as a percent)	2.87%	2.83%
Weighted-average assumptions used to determine net periodic pension expense
Discount rate: (as a percent)	2.83%	3.67%	4.05%
Expected long-term rate on plan assets: (as a percent)	7.25%	7.25%	7.25%
Plan Assets
Actual asset allocation (as a percent)	100.00%	100.00%
Domestic plans | Equity securities
Plan Assets
Actual asset allocation (as a percent)	62.00%	60.00%
Domestic plans | Fixed income securities
Plan Assets
Actual asset allocation (as a percent)	18.00%	20.00%
Domestic plans | Other
Plan Assets
Actual asset allocation (as a percent)	20.00%	20.00%
Domestic plans | Minimum | Equity securities
Plan Assets
Target Asset Allocation (as a percent)	45.00%
Domestic plans | Minimum | Fixed income securities
Plan Assets
Target Asset Allocation (as a percent)	15.00%
Domestic plans | Minimum | Other
Plan Assets
Target Asset Allocation (as a percent)	0.00%
Domestic plans | Maximum | Equity securities
Plan Assets
Target Asset Allocation (as a percent)	75.00%
Domestic plans | Maximum | Fixed income securities
Plan Assets
Target Asset Allocation (as a percent)	45.00%
Domestic plans | Maximum | Other
Plan Assets
Target Asset Allocation (as a percent)	25.00%
International plans
Key weighted-average assumptions used in the measurement of the company's projected benefit obligations
Discount rate (as a percent)	1.20%	1.20%
Rate of compensation increase (as a percent)	3.00%	3.00%
Weighted-average assumptions used to determine net periodic pension expense
Discount rate: (as a percent)	1.20%	1.50%	1.90%
Expected long-term rate on plan assets: (as a percent)	2.50%	2.90%	3.60%