Guarantees, Other Contingent Liabilities, And Other Matters (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020
Guarantees, Other Contingent Liabilities, and Other Matters [Line Items]
Face amount of guarantee including unpaid accrued interest	$ 1,000	$ 2,000	$ 3,000
Fair value of the guarantees	100	785	103
Other contingent liabilities	1,000
Net provision for losses (recoveries) on advances and guaranteed loans to suppliers	57	(165)
Stock repurchase program authorized amount	100,000
Stock repurchase program remaining authorized repurchase amount	56,100
Advances to suppliers [Member]
Guarantees, Other Contingent Liabilities, and Other Matters [Line Items]
Advances to suppliers current and non-current	83,000	101,000	153,000
Valuation allowances	16,000	18,000	16,000
Net provision for losses (recoveries) on advances and guaranteed loans to suppliers	100	(200)
Recoverable value added tax credits [Member]
Guarantees, Other Contingent Liabilities, and Other Matters [Line Items]
Aggregate balance of recoverable value added tax credits	54,000	61,000	52,000
Valuation allowances	17,000	$ 18,000	$ 19,000
Santa Catarina [Member]
Guarantees, 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]
Guarantees, Other Contingent Liabilities, and Other Matters [Line Items]
Estimate of possible loss on remaining VAT audit assessment	0
Santa Catarina [Member] | Maximum [Member]
Guarantees, Other Contingent Liabilities, and Other Matters [Line Items]
Estimate of possible loss on remaining VAT audit assessment	9,000
Parana [Member]
Guarantees, 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]
Guarantees, Other Contingent Liabilities, and Other Matters [Line Items]
Estimate of possible loss on remaining VAT audit assessment	0
Parana [Member] | Maximum [Member]
Guarantees, Other Contingent Liabilities, and Other Matters [Line Items]
Estimate of possible loss on remaining VAT audit assessment	$ 3,000