Restructuring (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Oct. 31, 2011	Oct. 31, 2010
Restructuring reserve roll forward
Beginning balance	$ 2,256
Non-cash write-offs	0	(951)
Cash payments	(1,351)
Ending balance	905
Employee Related [Member]
Restructuring reserve roll forward
Beginning balance	2,207
Non-cash write-offs	0
Cash payments	(1,351)
Ending balance	856
Asset Write-offs [Member]
Restructuring reserve roll forward
Beginning balance	0
Non-cash write-offs	0
Cash payments	0
Ending balance	0
Other [Member]
Restructuring reserve roll forward
Beginning balance	49
Non-cash write-offs	0
Cash payments	0
Ending balance	$ 49