Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Apr. 30, 2015	Apr. 30, 2014
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 3,992	$ 2,324
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	80,346,488	77,887,663
Common stock, shares outstanding	80,146,488	77,637,663
Treasury stock, shares	200,000	250,000