Goodwill (Details) (USD $)	12 Months Ended
	Jul. 31, 2011	Jul. 31, 2010
Goodwill [Roll Forward]
Balance as of July 31, 2009	$ 175,870,000	$ 166,327,000
Goodwill recorded during the period	19,309,000	12,599,000
Effect of foreign currency translation	3,441,000	(3,056,000)
Balance as of July 31, 2009	198,620,000	175,870,000
Goodwill, Acquired During Period	19,309,000	12,599,000
Goodwill impairment losses	$ 21,800,000