Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation Plans (Narrative) (Details)

v3.24.2
Stock-Based Compensation Plans (Narrative) (Details) - USD ($)
$ in Millions
12 Months Ended
May 31, 2024
May 31, 2023
May 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Shares authorized for grant 46,500,000    
Shares available for future grants 13,500,000    
Stock-based compensation expense $ 61.1 $ 62.6 $ 52.8
Income tax benefits related to stock-based compensation 12.7 $ 12.1 $ 9.8
Total unrecognized compensation cost related to all unvested stock-based awards $ 92.0    
Weighted-average period in years of all unvested stock-based awards 2 years 7 months 6 days    
Stock Options [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Contractual life 10 years    
Time-Based RSUs [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Awards granted [1] 500,000    
Performance-Based RSUs [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Performance period 2 years    
Service period 1 year    
Awards granted [1] 200,000    
Time-Based Restricted Stock Awards [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 1 year    
Awards granted 0 0  
Performance-Based Restricted Stock Awards [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Performance period 2 years    
Service period 1 year    
Awards granted 0 0  
Director [Member] | Stock Options [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 1 year    
Non-Executive [Member] | Time-Based RSUs [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period     5 years
Executive [Member] | Time-Based RSUs [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 3 years    
Outside Directors [Member] | Time-Based RSUs [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 1 year    
Tranche One [Member] | Time-Based Restricted Stock Awards [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting percentage 33.30%    
Tranche One [Member] | Officer [Member] | Stock Options [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting percentage 33.30%    
Tranche One [Member] | Non-Executive [Member] | Time-Based RSUs [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting percentage     20.00%
Tranche One [Member] | Executive [Member] | Time-Based RSUs [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting percentage 33.30%    
Employee Stock Purchase Plan [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock-based compensation expense $ 0.0 $ 0.0 $ 0.0
Discount to the market price 5.00% 5.00% 5.00%
Minimum [Member] | Non-Executive [Member] | Time-Based RSUs [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 4 years 4 years  
Maximum [Member] | Non-Executive [Member] | Time-Based RSUs [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 5 years 5 years  
Maximum [Member] | Employee Stock Purchase Plan [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Discount to the market price 15.00%    
[1] For performance-based RSUs, granted number assumes achievement of performance goals at target. Actual number of shares to be earned may differ from this amount.