Quarterly report pursuant to Section 13 or 15(d)

Supplemental Balance Sheet Information (Details)

v2.4.0.6
Supplemental Balance Sheet Information (Details) (USD $)
In Millions, unless otherwise specified
Jan. 31, 2012
Apr. 30, 2011
Supplemental Balance Sheet Information [Abstract]    
Deferred revenue $ 14.2 $ 11.3