Other Contingent Liabilities And Other Matters (Narrative) (Details) - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Mar. 31, 2021
Other Contingent Liabilities and Other Matters [Line Items]
Other contingent liabilities	$ 1,000
Net provision for losses (recoveries) on advances to suppliers	(44)	$ 348
Long-term Line of Credit	150,000
Loans Payable	150,000
Stock repurchase program authorized amount	100,000
Stock repurchase program remaining authorized repurchase amount	100,000
Five-year term loan [Member]
Other Contingent Liabilities and Other Matters [Line Items]
Issuance of long-term debt	75,000
Loans Payable	225,000
Seven-year term loan [Member]
Other Contingent Liabilities and Other Matters [Line Items]
Issuance of long-term debt	75,000
Loans Payable	295,000
Advances to suppliers [Member]
Other Contingent Liabilities and Other Matters [Line Items]
Advances to suppliers current and non-current	98,000	81,000	$ 144,000
Valuation allowances	14,000	14,000	18,000
Net provision for losses (recoveries) on advances to suppliers	(44)	300
Recoverable value added tax credits [Member]
Other Contingent Liabilities and Other Matters [Line Items]
Aggregate balance of recoverable value added tax credits	55,000	51,000	49,000
Valuation allowances	20,000	$ 18,000	$ 19,000
Santa Catarina [Member]
Other Contingent Liabilities and Other Matters [Line Items]
Brazil audit assessment for tax, penalties, and interest on recoverable value added tax credits	9,000
Reduced Brazil audit assessment for tax, penalties, and interest on recoverable value added tax credits	9,000
Loss contingency amount accrued	0
Santa Catarina [Member] | Minimum [Member]
Other Contingent Liabilities and Other Matters [Line Items]
Estimate of possible loss on remaining VAT audit assessment	0
Santa Catarina [Member] | Maximum [Member]
Other Contingent Liabilities and Other Matters [Line Items]
Estimate of possible loss on remaining VAT audit assessment	9,000
Parana [Member]
Other Contingent Liabilities and Other Matters [Line Items]
Brazil audit assessment for tax, penalties, and interest on recoverable value added tax credits	10,000
Reduced Brazil audit assessment for tax, penalties, and interest on recoverable value added tax credits	3,000
Loss contingency amount accrued	0
Parana [Member] | Minimum [Member]
Other Contingent Liabilities and Other Matters [Line Items]
Estimate of possible loss on remaining VAT audit assessment	0
Parana [Member] | Maximum [Member]
Other Contingent Liabilities and Other Matters [Line Items]
Estimate of possible loss on remaining VAT audit assessment	$ 3,000