Restructuring Charges - Additional Information (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 Charge	$ 197	$ 267	$ 731	$ 299
Fiscal Year 2017 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring Charge	$ 200		$ 700