Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Jul. 31, 2016	Jul. 31, 2015
Deferred tax assets:
Net operating loss carryforwards	$ 81,822	$ 75,812
Accrued liabilities	1,482	1,280
Tax credit carryforwards	5,859	3,759
Fixed assets	269	157
Deferred revenue	2,207	733
Stock-based compensation	1,996	806
Other	1	1
Valuation allowance	(92,846)	(81,341)
Total deferred tax assets	790	1,207
Deferred tax liabilities:
Intangible assets	(684)	(1,163)
Total deferred tax liabilities	(684)	(1,163)
Net deferred tax assets	106	44
Current deferred tax assets	0	1,076
Current valuation allowance	0	(1,050)
Non-current deferred tax assets	92,908	81,477
Non-current valuation allowance	(92,802)	(80,291)
Current deferred tax liabilities	0	(5)
Non-current deferred tax liabilities	0	(1,163)
Net deferred tax assets	$ 106	$ 44