Pension and Other Post-retirement Benefit Plans - Fair Value (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
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	10.00%
Other
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations	7.00%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	15.00%
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	15.00%
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	60.00%
Pension
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 71,491	$ 10,004	$ 10,268
Actual return on plan assets	2,594	1,099
Employer contributions	4,766	1,176
Settlements	(5,659)	(58)
Benefits paid	(1,128)	(1,120)
Foreign currency exchange rate change	3,831	(1,361)
Pension | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	193	86
Pension | International equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	22,391	1,760
Pension | International bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	43,742	6,275
Pension | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	697	580
Pension | Mutual Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,468	1,303
Pension | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	193	86
Pension | Level 1 | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	193	86
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	70,601	9,338
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	22,391	1,760
Pension | Level 2 | International bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	43,742	6,275
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	4,468	1,303
Pension | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	697	580	$ 611
Actual return on plan assets	41	20
Employer contributions	219	198
Benefits paid	(233)	(211)
Foreign currency exchange rate change	90	(38)
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	$ 697	$ 580