Pension and Other Benefit Plans (Narrative) (Details) - USD ($)	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	100.00%
Total liabilities	$ 912,904,000	$ 620,283,000
Accrued liabilities	118,187,000	110,816,000
Other non-current liabilities	192,610,000	191,920,000
Charge recorded for contributions to defined contribution plans	4,540,000	4,063,000	$ 5,239,000
Fair value of plan assets at beginning of year	286,678,000
Fair value of plan assets at end of year	271,985,000	286,678,000
(Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	1,169,000
Fair value of plan assets at end of year	1,160,000	1,169,000
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax	29,230,000	51,540,000
Defined Benefit Plan, Benefit Obligation	356,974,000	404,841,000	459,866,000
Curtailment charge	0	(19,038,000)	$ 0
Employer contribution	$ 5,442,000	$ 1,316,000
Discount rate	3.35%	2.62%	2.79%
Net periodic pension cost (benefit)	$ (470,000)	$ 22,104,000	$ 2,290,000
Fair value of plan assets at beginning of year	286,678,000	313,366,000
Fair value of plan assets at end of year	271,985,000	286,678,000	$ 313,366,000
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together [Line Items]
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Plan Assets	121,110,000	283,280,000
Investment Holdings [Line Items]
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Assets Transferred to (from) Plan	2,176,000	3,910,000
Pension Plans | (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fixed income securities investment return	21,000
Disbursements	$ 30,000
Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Retirement age	65 years
Percentage of premium contributed	100.00%
Net periodic pension cost (benefit)	$ 187,000
Postretirement Benefit Plans | American Association of Retired Persons
Defined Benefit Plan Disclosure [Line Items]
Employer contribution	35
Defined Benefit Postretirement Life Insurance
Defined Benefit Plan Disclosure [Line Items]
Net periodic pension cost (benefit)	132,000
Total liabilities	4,645,000
Accrued liabilities	4,452,000
Other non-current liabilities	193,000
Cash Surrender Value of Life Insurance	$ 3,590,000	$ 3,496,000
Maximum [Member] | Equity Securities [Member] | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage				13.00%
Maximum [Member] | Fixed Income Securities [Member] | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage				87.00%
Minimum | Equity Securities [Member] | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage				23.00%
Minimum | Fixed Income Securities [Member] | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage				77.00%