v3.26.1
Pensions and Other Benefit Plans - Narrative (Details)
 12 Months Ended
Mar. 31, 2026
USD ($)
yr
Mar. 31, 2025
USD ($)
pensionPlan
Mar. 31, 2024
USD ($)
pensionPlan
Sep. 30, 2024
USD ($)
Defined Benefit Plan Disclosure [Line Items]        
Settlement charge $ 0 $ 23,634,000 $ 4,984,000  
Short term pension liabilities 5,614,000 3,709,000    
Accrued liabilities 249,009,000 113,907,000    
Other liabilities, noncurrent 525,151,000 178,538,000    
Charge recorded for contributions to defined contribution plans 6,770,000 6,686,000 6,288,000  
Pension Plans        
Defined Benefit Plan Disclosure [Line Items]        
Fair value of plan assets 0 0    
Defined benefit plan, expected future employer contributions, next fiscal year 7,418,000      
Employer contribution 4,487,000 5,136,000    
Defined benefit plan, net periodic benefit cost (credit) 2,280,000 27,030,000 $ 7,945,000  
Liability, defined benefit plan, noncurrent 81,481,000 62,675,000    
Short term pension liabilities $ 5,614,000 3,709,000    
Postretirement Benefit Plans        
Defined Benefit Plan Disclosure [Line Items]        
Retirement age | yr 65      
Percentage of premium contributed 100.00%      
Defined benefit plan, net periodic benefit cost (credit) $ 143,000      
Liability, defined benefit plan 567,000      
Liability, defined benefit plan, noncurrent 465,000      
Short term pension liabilities 102,000      
Postretirement Benefit Plans | American Association of Retired Persons        
Defined Benefit Plan Disclosure [Line Items]        
Employer contribution 35      
Defined Benefit Postretirement Life Insurance        
Defined Benefit Plan Disclosure [Line Items]        
Defined benefit plan, net periodic benefit cost (credit) 35,000      
Liability, defined benefit pension plan 2,975,000      
Accrued liabilities 2,898,000      
Other liabilities, noncurrent 77,000      
Cash surrender value of life insurance 2,556,000 $ 2,474,000    
United States        
Defined Benefit Plan Disclosure [Line Items]        
Number of pension plans settled | pensionPlan   1    
Plan assets in excess of benefit obligation       $ 6,974,000
Plan assets in excess of benefit obligation, remaining surplus $ 3,938,000,000      
Canada        
Defined Benefit Plan Disclosure [Line Items]        
Number of pension plans settled | pensionPlan     2