Schedule II - Valuation And Qualifying Accounts (Details) - USD ($)	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Allowance for doubtful accounts [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 1,783	$ 3,947	$ 9,099
Net Additions (Reversals) Charged to Expense	1,358	(2,006)	(5,071)
Additions Charged to Other Accounts	0	0	0
Deductions	(156)	(158)	(81)
Balance at End of Period	2,985	1,783	3,947
Allowance for supplier accounts [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	21,720	27,074	28,865
Net Additions (Reversals) Charged to Expense	(2,339)	3,730	(857)
Additions Charged to Other Accounts	0	0	0
Deductions	(1,276)	(9,084)	(934)
Balance at End of Period	18,105	21,720	27,074
Allowance for recoverable taxes [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	14,679	12,552	18,752
Net Additions (Reversals) Charged to Expense	3,535	1,732	(3,392)
Additions Charged to Other Accounts	0	0	0
Deductions	(1,033)	395	(2,808)
Balance at End of Period	$ 17,181	$ 14,679	$ 12,552