Pension and Other Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Other	$ (4,082)	$ 0
Change in pension liability and postretirement obligations, net of tax	(12,737)	(10,108)	$ 4,685
Defined Benefit Plan, Benefit Obligation, Business Combination	0	72,638
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Remeasurement due to Settlement	(65)	(883)
Defined Benefit Plan, Plan Assets, Payment for Settlement	(65)	(883)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	321,440
Fair value of plan assets at end of year	326,745	321,440
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment	5	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	0	247	0
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(35,888)	(31,757)
Change in pension liability and postretirement obligations, net of tax	17	(57)	2,452
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	471,871	421,147
Service cost	2,580	1,779	2,187
Interest cost	16,488	16,648	13,926
Actuarial (gain) loss	(2,467)	(4,475)
Benefits paid	(35,888)	(31,757)
Foreign exchange rate changes	13,847	(3,226)
Benefit obligation at end of year	462,284	471,871	421,147
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	321,440	317,868
Actual gain (loss) on plan assets	29,930	30,164
Employer contribution	11,211	6,140
Foreign exchange rate changes	117	(92)
Fair value of plan assets at end of year	326,745	321,440	317,868
Funded status	(135,539)	(150,431)
Unrecognized actuarial loss		(83,030)
Unrecognized prior service cost	0	8
Net amount recognized	(69,707)	(67,393)
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax	65,832	83,038
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Accrued liabilities	(3,814)	(3,310)
Other non-current liabilities	(131,725)	(147,121)
Net amount recognized	(69,707)	(67,393)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	690	(621)	(1,208)
Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation, Benefits Paid	311	344
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	4,111	5,144
Interest cost	126	152	189
Actuarial (gain) loss	642	841
Benefit obligation at end of year	3,284	4,111	5,144
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Funded status	(3,284)	(4,111)
Unrecognized actuarial loss	(660)	(23)
Net amount recognized	(3,944)	(4,134)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Accrued liabilities	(449)	(519)
Other non-current liabilities	(2,835)	(3,592)
Net amount recognized	(3,944)	(4,134)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	121	152	$ 278
Equity Securities [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	220,497
Fair value of plan assets at end of year	136,777	220,497
Fixed Income Securities [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	99,700
Fair value of plan assets at end of year	174,359	99,700
Real Estate Funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0
Fair value of plan assets at end of year	13,230	0
Cash and Cash Equivalents [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	1,243
Fair value of plan assets at end of year	2,379	1,243
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	182,688
Fair value of plan assets at end of year	85,008	182,688
Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	149,435
Fair value of plan assets at end of year	78,344	149,435
Fair Value, Inputs, Level 1 [Member] | Fixed Income Securities [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	32,010
Fair value of plan assets at end of year	0	32,010
Fair Value, Inputs, Level 1 [Member] | Real Estate Funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	4,285
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	1,243
Fair value of plan assets at end of year	2,379	1,243
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	120,586
Fair value of plan assets at end of year	121,271	120,586
Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	71,062
Fair value of plan assets at end of year	0	71,062
Fair Value, Inputs, Level 2 [Member] | Fixed Income Securities [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	49,524
Fair value of plan assets at end of year	121,271	49,524
Fair Value, Inputs, Level 2 [Member] | Real Estate Funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0
Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0
Fair value of plan assets at end of year	0	0
(Level 3)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	18,166
Fair value of plan assets at end of year	18,468	18,166
(Level 3) | Equity Securities [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0
Fair value of plan assets at end of year	0	0
(Level 3) | Fixed Income Securities [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	18,166
Fair value of plan assets at end of year	18,468	18,166
(Level 3) | Real Estate Funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0
(Level 3) | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0
Fair value of plan assets at end of year	$ 0	$ 0