Income Taxes - Net Deferred Tax Assets (Detail) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2012	Jul. 31, 2011
Deferred tax assets:
Net operating loss carry forwards	$ 288,381	$ 284,269
Credit carry forwards	21,457	21,467
Restructuring and related accruals	4,442	4,405
Accrued expenses	810	847
Share based compensation expense	5,035	4,000
Capital loss carry forwards	783	934
Depreciation	5,646	5,829
Other, net	6,411	6,602
Total net deferred tax assets	332,965	328,353
Valuation allowance	(332,748)	(328,277)
Net deferred tax assets	$ 217	$ 76