v3.26.1
Employee Benefit Plans (Details) - USD ($)
$ in Millions
 12 Months Ended
May 31, 2026
May 31, 2025
May 31, 2024
Employee benefit plans      
Pension expense $ 3.9 $ 3.9 $ 3.7
Benefit plan remaining surplus plan assets 7.6    
Change in projected benefit obligation:      
Non-cash, after-tax pension settlement charge 16.1    
Defined Benefit Pension Plans      
Employee benefit plans      
Pension expense 2.0 1.4 1.3
Merged U.S. Plan      
Change in the fair value of plan assets:      
Funded status at end of year 26.7    
Netherlands Plan      
Change in projected benefit obligation:      
Projected benefit obligation at beginning of year 53.8 52.7  
Service cost 0.2 0.2  
Interest cost 2.0 1.9  
Net actuarial gain (3.8) (1.1)  
Benefits and administrative payments (2.4) (2.2)  
Foreign currency translation adjustment 1.5 2.3  
Projected benefit obligation at end of year 51.3 53.8 52.7
Change in the fair value of plan assets:      
Fair value of plan assets at beginning of year 53.6 51.4  
Actual return on plan assets 0.8 1.7  
Benefits and administrative payments (2.4) (2.2)  
Employer contributions 0.2 0.4  
Foreign currency translation adjustment (1.5) (2.3)  
Fair value of plan assets at end of year 53.7 53.6 51.4
Funded status at end of year 2.4 (0.2)  
Accumulated other comprehensive loss 4.9 6.8  
Accumulated benefit obligation 49.9 51.8  
Net Periodic Benefit Cost      
Service cost 0.2 0.2 0.2
Interest cost 2.0 1.9 1.9
Expected return on plan assets $ (2.6) $ (2.5) $ (2.4)
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)
Recognized net actuarial loss   $ 0.1  
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]   Other Nonoperating Income (Expense)  
Total $ (0.4) $ (0.3) $ (0.3)
Assumptions      
Discount rate (as a percent) 4.30% 3.70%  
Pension expenses for discount rate 3.70% 3.60% 3.70%
Benefit plan assumptions used expected long term rate of return 4.80% 4.80% 4.80%