Acquisitions and Divestitures (Details) (USD $) In Thousands	Jul. 31, 2011	Jul. 31, 2010
Summary of the combined estimated fair values of the assets acquired and liabilities assumed at the date of the acquisitions
Current assets net of cash	$ 1,876	$ 5,313
Property, plant & equipment	415	743
Goodwill	4,792	20,266
Total assets acquired net of cash	9,416	35,632
Liabilities assumed	1,446	5,201
Net cash paid for acquisitions	7,970	30,431
Customer relationships [Member]
Summary of the combined estimated fair values of the assets acquired and liabilities assumed at the date of the acquisitions
Other intangible assets	1,846	7,970
Trademarks [Member]
Summary of the combined estimated fair values of the assets acquired and liabilities assumed at the date of the acquisitions
Other intangible assets		1,340
Non-compete agreements [Member]
Summary of the combined estimated fair values of the assets acquired and liabilities assumed at the date of the acquisitions
Other intangible assets	$ 487