Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Jul. 31, 2015	Jul. 31, 2014
Deferred tax assets:
Net operating loss carryforwards	$ 298,924	$ 298,426
Credit carryforwards	21,301	21,301
Restructuring and related accruals	3,502	3,502
Capital loss carryforwards	672	672
Depreciation	971	971
Other, net	695	695
Total net deferred tax assets	326,065	325,567
Valuation allowance	(326,065)	(325,567)
Net deferred tax assets	$ 0	$ 0