Pension and Other Post-retirement Benefit Plans - Fair Value (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations	100.00%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	100.00%
Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations	1.00%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	1.00%
Other
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations	7.00%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	4.00%
International Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations	31.00%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	34.00%
International Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations	61.00%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	61.00%
Pension
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 63,902	$ 71,491	$ 10,004
Actual return on plan assets	1,165	2,594
Employer contributions	7,882	4,766
Settlements	(12,379)	(5,659)
Benefits paid	(1,096)	(1,128)
Foreign currency exchange rate change	(3,161)	3,831
Pension | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	319	193
Pension | International equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	19,965	22,391
Pension | International bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	39,030	43,742
Pension | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	642	697
Pension | Mutual Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,946	4,468
Pension | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	319	193
Pension | Level 1 | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	319	193
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	62,941	70,601
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	19,965	22,391
Pension | Level 2 | International bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	39,030	43,742
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	3,946	4,468
Pension | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	642	697	$ 580
Actual return on plan assets	20	41
Employer contributions	233	219
Benefits paid	(247)	(233)
Foreign currency exchange rate change	(61)	90
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	$ 642	$ 697