Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jan. 31, 2015	Apr. 30, 2014
Allowance for doubtful accounts	$ 3,418	$ 2,324
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000us-gaap_CommonStockSharesAuthorized	150,000,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued	79,629,679us-gaap_CommonStockSharesIssued	77,887,663us-gaap_CommonStockSharesIssued
Common stock, shares outstanding	79,379,679us-gaap_CommonStockSharesOutstanding	77,637,663us-gaap_CommonStockSharesOutstanding
Treasury stock, shares	250,000us-gaap_TreasuryStockShares	250,000us-gaap_TreasuryStockShares

A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

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Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

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