Benefit Plans (Details Textual) - USD ($)
$ in Thousands
12 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Mar. 31, 2018
Defined Contribution Plan, Employer Discretionary Contribution Amount $ 27,818 $ 25,935 $ 24,037
Defined Contribution Plan, Fair Value of Plan Assets $ 668,960    
STERIS Corporation shares held in defined contribution plan 555,080    
Fair value of STERIS Corporatio stock held in defined contribution plan $ 77,695    
Defined Contribution Plan, Dividends Paid 855 826 $ 781
Deferred Compensation Plan Assets $ 1,273 $ 1,400  
Equity Securities [Member]      
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage 75.00%    
Debt Securities      
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage 25.00%