Restructuring Accrual Activity (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2018	Apr. 30, 2017	Apr. 30, 2018	Apr. 30, 2017
Restructuring Cost and Reserve [Line Items]
Beginning Balance			$ 86	$ 876
Additions to expense	$ 3	$ 187	688	592
Accretion				253
Cash paid			(699)	(1,453)
Ending Balance	75	268	75	268
Severance Costs
Restructuring Cost and Reserve [Line Items]
Beginning Balance			21	142
Additions to expense			359	348
Cash paid			(379)	(348)
Ending Balance	1	142	1	142
Facility Lease
Restructuring Cost and Reserve [Line Items]
Beginning Balance			65	734
Additions to expense			329	244
Accretion				253
Cash paid			(320)	(1,105)
Ending Balance	$ 74	$ 126	$ 74	$ 126