Guarantees, Other Contingent Liabilities, And Other Matters (Narrative) (Details) - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Mar. 31, 2015
Guarantees, Other Contingent Liabilities, and Other Matters [Line Items]
Company total exposure under guarantees	$ 25,000
Face amount of guarantee including unpaid accrued interest	26,000	$ 35,000	$ 17,000
Fair value of the guarantees	1,356	1,797	1,674
Other contingent liabilities	3,000
Advances to suppliers current and non-current	71,000	115,000	156,000
Valuation allowance amount related to advances to suppliers	27,000	38,000	35,000
Net provision for losses (recoveries) on advances and guaranteed loans to suppliers	(4,354)	(2,497)
Aggregate balance of recoverable value added tax credits	52,000	69,000	60,000
Valuation allowance on recoverable value added tax credits	21,000	$ 37,000	$ 23,000
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	12,000
Reduced Brazil audit assessment for tax, penalties, and interest on recoverable value added tax credits	10,000
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	10,000
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	14,000
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	$ 12,000