Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013
Allowance for doubtful accounts	$ 2,324	$ 2,371
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	77,887,663	73,925,136
Common stock, shares outstanding	77,637,663	73,675,136
Treasury stock, shares	250,000	250,000