Annual report pursuant to Section 13 and 15(d)

Pension and Other Post-retirement Benefit Plans - Fair Value (Details)

v3.20.1
Pension and Other Post-retirement Benefit Plans - Fair Value (Details) - USD ($)
$ in Thousands
12 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Mar. 31, 2018
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage 100.00%    
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage 100.00%    
Insurance contracts      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage 1.00%    
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage 1.00%    
Other      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage 6.00%    
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage 4.00%    
International Equities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage 31.00%    
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage 34.00%    
International Bonds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage 62.00%    
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage 61.00%    
Pension      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets $ 61,201 $ 63,902 $ 71,491
Actual return on plan assets (543) 1,165  
Employer contributions 10,208 7,882  
Settlements (7,700) (12,379)  
Benefits paid (5,153) (1,096)  
Foreign currency exchange rate change 487 (3,161)  
Pension | Cash and Cash Equivalents [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 96 319  
Pension | International equities      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 18,895 19,965  
Pension | International bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 37,799 39,030  
Pension | Insurance contracts      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 629 642  
Pension | Mutual Fund [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 3,782 3,946  
Pension | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 96 319  
Pension | Level 1 | Cash and Cash Equivalents [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 96 319  
Pension | Level 1 | International equities      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0 0  
Pension | Level 1 | International bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0 0  
Pension | Level 1 | Insurance contracts      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0 0  
Pension | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 60,476 62,941  
Pension | Level 2 | Cash and Cash Equivalents [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0 0  
Pension | Level 2 | International equities      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 18,895 19,965  
Pension | Level 2 | International bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 37,799 39,030  
Pension | Level 2 | Insurance contracts      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0 0  
Pension | Level 2 | Mutual Fund [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 3,782 3,946  
Pension | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 629 642 $ 697
Actual return on plan assets 18 20  
Employer contributions 226 233  
Benefits paid (241) (247)  
Foreign currency exchange rate change (16) (61)  
Pension | Level 3 | Cash and Cash Equivalents [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0 0  
Pension | Level 3 | International equities      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0 0  
Pension | Level 3 | International bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0 0  
Pension | Level 3 | Insurance contracts      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets $ 629 $ 642