Benefit Plans (Assumptions used in calculating benefit obligations and net periodic benefit cost) (Details)
12 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Mar. 31, 2018
Synergy Health PLC Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate 2.40% 2.50%  
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets 4.80% 5.02% 4.97%
Isotron [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate 1.60% 1.20%  
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets 1.20% 1.60% 1.60%
Daniken [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate 0.20% 0.85%  
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets 0.65% 1.20% 1.40%
Radeberg [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate 1.60% 1.60%  
Allershausen [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate 0.50% 1.60%  
Harwell Dosimeters [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate 2.45% 2.35%  
Other Pension Plans, Defined Benefit [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate 3.00% 3.50%