Annual report pursuant to Section 13 and 15(d)

Business Segments (Parenthetical) (Detail)

v2.4.0.6
Business Segments (Parenthetical) (Detail) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Apr. 30, 2012
Apr. 30, 2011
Segment Reporting Information [Line Items]    
Change in fair value of acquisition-related contingent consideration $ (2,196) $ (4,919)