Summary of Net Restructuring Charges (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2018	Jan. 31, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring, net	$ 4	$ 776	$ 41	$ 2,150
Cost of revenue
Restructuring Cost and Reserve [Line Items]
Restructuring, net		154	8	735
Selling, general and administrative
Restructuring Cost and Reserve [Line Items]
Restructuring, net	$ 4	$ 622	$ 33	$ 1,415