Fair Value Measurements (Assets and liabilities measured at fair value on recurring bases) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Marketable securities	$ 8,534	$ 7,322
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Plan Assets	3,790
Marketable securities | Quoted Prices in Active Markets for Indentical Assets (Level 1)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Marketable securities	8,534	7,322
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Plan Assets	3,790
Marketable securities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Marketable securities	0	0
Marketable securities | Significant unobservable Inputs (Level 3)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Marketable securities	0	0
Variable Annuity [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Annuity contract	2,107	2,059
Variable Annuity [Member] | Quoted Prices in Active Markets for Indentical Assets (Level 1)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Annuity contract	0	0
Variable Annuity [Member] | Significant Other Observable Inputs (Level 2)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Annuity contract	2,107	2,059
Variable Annuity [Member] | Significant unobservable Inputs (Level 3)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Annuity contract	0	0
Foreign exchange contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	24	285
Foreign exchange contracts | Quoted Prices in Active Markets for Indentical Assets (Level 1)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	0	0
Foreign exchange contracts | Significant Other Observable Inputs (Level 2)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	24	285
Foreign exchange contracts | Significant unobservable Inputs (Level 3)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	0	0
Term loan
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Term loan	(256,482)	(239,899)
Term loan | Quoted Prices in Active Markets for Indentical Assets (Level 1)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Term loan	0	0
Term loan | Significant Other Observable Inputs (Level 2)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Term loan	(256,482)	(239,899)
Term loan | Significant unobservable Inputs (Level 3)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Term loan	0	0
Assets [Member] | Interest Rate Swap [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities		(3,296)
Assets [Member] | Interest Rate Swap [Member] | Quoted Prices in Active Markets for Indentical Assets (Level 1)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities		0
Assets [Member] | Interest Rate Swap [Member] | Significant Other Observable Inputs (Level 2)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities		(3,296)
Assets [Member] | Interest Rate Swap [Member] | Significant unobservable Inputs (Level 3)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities		0
Assets [Member] | Cross Currency Interest Rate Contract [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	197	1,750
Assets [Member] | Cross Currency Interest Rate Contract [Member] | Quoted Prices in Active Markets for Indentical Assets (Level 1)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	0	0
Assets [Member] | Cross Currency Interest Rate Contract [Member] | Significant Other Observable Inputs (Level 2)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	197	1,750
Assets [Member] | Cross Currency Interest Rate Contract [Member] | Significant unobservable Inputs (Level 3)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	0	0
Liability [Member] | Interest Rate Swap [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	(2,875)
Liability [Member] | Interest Rate Swap [Member] | Quoted Prices in Active Markets for Indentical Assets (Level 1)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	0
Liability [Member] | Interest Rate Swap [Member] | Significant Other Observable Inputs (Level 2)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	(2,875)
Liability [Member] | Interest Rate Swap [Member] | Significant unobservable Inputs (Level 3)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	0
Liability [Member] | Cross Currency Interest Rate Contract [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	(14,289)	(5,254)
Liability [Member] | Cross Currency Interest Rate Contract [Member] | Quoted Prices in Active Markets for Indentical Assets (Level 1)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	0	0
Liability [Member] | Cross Currency Interest Rate Contract [Member] | Significant Other Observable Inputs (Level 2)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	(14,289)	(5,254)
Liability [Member] | Cross Currency Interest Rate Contract [Member] | Significant unobservable Inputs (Level 3)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	$ 0	$ 0