Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jan. 31, 2013	Apr. 30, 2012
Allowance for doubtful accounts	$ 1,564	$ 788
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	72,948,155	58,779,937
Common stock, shares outstanding	72,698,155	58,529,937
Treasury stock, shares	250,000	250,000