Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jul. 31, 2017	Apr. 30, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 1,037	$ 1,260
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	85,785,521	84,487,847
Common stock, shares outstanding	85,585,521	84,287,847
Treasury stock, shares	200,000	200,000