Aggregate Cash and Cash Equivalents (Detail) - USD ($) $ in Thousands	Apr. 30, 2016	Jul. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 3,993	$ 10,943
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Market Value	3,993	10,943
Cash and cash equivalents
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,993	10,943
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Market Value	$ 3,993	$ 10,943