Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	Jul. 31, 2012	Apr. 30, 2012
Condensed Consolidated Balance Sheets [Abstract]
Allowance for doubtful accounts	$ 878	$ 788
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	69,029,568	58,779,937
Common stock, shares outstanding	68,779,568	58,529,937
Treasury stock, shares	250,000	250,000