Pension and Other Benefits (Details) - USD ($)	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Change in pension liability and postretirement obligations, net of tax	$ 23,896,000	$ 5,166,000	$ (12,737,000)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	321,902,000
Fair value of plan assets at end of year	313,366,000	321,902,000
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	4,945,000
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation	410,181,000	395,202,000
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Plan Assets	254,508,000	264,211,000
Assets for Plan Benefits, Defined Benefit Plan	6,587,000	6,424,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment	0	0	5,000
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(26,852,000)	(27,068,000)
Change in pension liability and postretirement obligations, net of tax	0	0	17,000
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	446,397,000	462,284,000
Service cost	1,139,000	1,078,000	2,580,000
Interest cost	14,759,000	15,526,000	16,488,000
Actuarial (gain) loss	26,193,000	4,074,000
Benefits paid	(26,852,000)	(27,068,000)
Foreign exchange rate changes	(1,770,000)	(9,497,000)
Benefit obligation at end of year	459,866,000	446,397,000	462,284,000
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	321,902,000	326,745,000
Actual gain (loss) on plan assets	7,512,000	11,333,000
Employer contribution	10,967,000	11,018,000
Foreign exchange rate changes	(163,000)	(126,000)
Fair value of plan assets at end of year	313,366,000	321,902,000	326,745,000
Funded status	(146,500,000)	(124,495,000)
Unrecognized actuarial loss		(73,836,000)
Net amount recognized	(40,622,000)	(50,659,000)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Accrued liabilities	(3,563,000)	(3,546,000)
Other non-current liabilities	(149,524,000)	(127,373,000)
Net amount recognized	(40,622,000)	(50,659,000)
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax	105,878,000	73,836,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	2,290,000	489,000	690,000
Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(192,000)	(250,000)
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	2,348,000	3,284,000
Interest cost	71,000	92,000	126,000
Actuarial (gain) loss	340,000	778,000
Benefit obligation at end of year	1,887,000	2,348,000	3,284,000
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Funded status	(1,887,000)	(2,348,000)
Net amount recognized	(3,304,000)	(3,630,000)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Accrued liabilities	(270,000)	(326,000)
Other non-current liabilities	(1,617,000)	(2,022,000)
Net amount recognized	(3,304,000)	(3,630,000)
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax	1,417,000	1,282,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(134,000)	(64,000)	$ 121,000
Equity Securities [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	103,017,000
Fair value of plan assets at end of year	94,336,000	103,017,000
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	205,957,000
Fair value of plan assets at end of year	199,613,000	205,957,000
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	9,978,000
Fair value of plan assets at end of year	9,401,000	9,978,000
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	2,950,000
Fair value of plan assets at end of year	10,016,000	2,950,000
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	66,072,000
Fair value of plan assets at end of year	91,320,000	66,072,000
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	59,703,000
Fair value of plan assets at end of year	52,084,000	59,703,000
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	602,000
Fair value of plan assets at end of year	24,014,000	602,000
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 beginning of year	2,817,000
Fair value of plan assets at end of year	5,206,000	2,817,000
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	2,950,000
Fair value of plan assets at end of year	10,016,000	2,950,000
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	153,941,000
Fair value of plan assets at end of year	139,498,000	153,941,000
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	0
Fair value of plan assets at end of year	0	0
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	153,941,000
Fair value of plan assets at end of year	139,498,000	153,941,000
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 beginning of year	0
Fair value of plan assets at end of year	0	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	5,701,000
Fair value of plan assets at end of year	5,503,000	5,701,000
(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	5,701,000
Fair value of plan assets at end of year	5,503,000	5,701,000
(Level 3) | 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	0	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
Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	96,188,000
Fair value of plan assets at end of year	77,045,000	96,188,000
Fair Value Measured at Net Asset Value Per Share [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	43,314,000
Fair value of plan assets at end of year	42,252,000	43,314,000
Fair Value Measured at Net Asset Value Per Share [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	45,713,000
Fair value of plan assets at end of year	30,598,000	45,713,000
Fair Value Measured at Net Asset Value Per Share [Member] | 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	7,161,000
Fair value of plan assets at end of year	4,195,000	7,161,000
Fair Value Measured at Net Asset Value Per Share [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