Quarterly report pursuant to Section 13 or 15(d)

Goodwill and intangible assets (Detail)

v2.4.0.6
Goodwill and intangible assets (Detail) (USD $)
In Thousands, unless otherwise specified
9 Months Ended
Apr. 30, 2013
Jul. 31, 2012
Apr. 30, 2013
Clinical Labs [Member]
Jul. 31, 2012
Clinical Labs [Member]
Apr. 30, 2013
Intangible Assets, Amortization Period [Member]
Goodwill $ 7,452 $ 7,452 $ 7,452 $ 7,452  
Finite-Lived Intangible Asset, Useful Life         7 years