Schedule II - Valuation And Qualifying Accounts (Details) (USD $)	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Allowance for doubtful accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 8,307	$ 5,603	$ 6,857
Net Additions (Reversals) Charged to Expense	1,788	4,244	(681)
Additions Charged to Other Accounts	0	0	0
Deductions	(2,127)	(1,540)	(573)
Balance at End of Period	7,968	8,307	5,603
Allowance for supplier accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	74,382	74,938	56,243
Net Additions (Reversals) Charged to Expense	1,623	11,929	18,666
Additions Charged to Other Accounts	0	0	0
Deductions	(21,612)	(12,485)	29
Balance at End of Period	54,393	74,382	74,938
Allowance for recoverable taxes [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	24,719	22,126	17,593
Net Additions (Reversals) Charged to Expense	4,005	2,564	3,785
Additions Charged to Other Accounts	0	0	0
Deductions	(2,680)	29	748
Balance at End of Period	$ 26,044	$ 24,719	$ 22,126