Restructuring (Details) (USD $) In Thousands	3 Months Ended								12 Months Ended
	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2011	Oct. 31, 2010	Jul. 31, 2010	Apr. 30, 2010	Jan. 31, 2010	Oct. 31, 2009	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009
Restructuring reserve roll forward
Beginning balance				$ 6,161				$ 5,322	$ 6,161	$ 5,322	$ 0
Restructuring charges	2,202	1,211	2,134	3,641	5,717	2,347	3,649	3,601	9,188	15,314	25,849
Non-cash write-offs									(2,155)	(2,260)	(2,469)
Other separation benefits										(1,178)	(1,178)
Cash payments									(10,938)	(12,215)	(16,880)
Ending balance	2,256				6,161				2,256	6,161	5,322
Employee Related [Member]
Restructuring reserve roll forward
Beginning balance				6,055				4,445	6,055	4,445	0
Restructuring charges									6,341	10,850	21,279
Non-cash write-offs											(368)
Other separation benefits											(1,178)
Cash payments									(10,189)	(9,240)	(15,288)
Ending balance	2,207				6,055				2,207	6,055	4,445
Asset Write-offs [Member]
Restructuring reserve roll forward
Beginning balance				0				0	0	0	0
Restructuring charges									2,155	2,260	2,101
Non-cash write-offs									(2,155)	(2,260)	(2,101)
Ending balance					0					0	0
Other [Member]
Restructuring reserve roll forward
Beginning balance				106				877	106	877	0
Restructuring charges									692	2,204	2,469
Cash payments									(749)	(2,975)	(1,592)
Ending balance	$ 49				$ 106				$ 49	$ 106	$ 877