Accrued Expenses and Other Current Liabilities - Product Warranty Rollforward (Details)	3 Months Ended
	Oct. 31, 2017 USD ($) credit	Oct. 31, 2016 USD ($)	Oct. 31, 2017 USD ($)
Business Acquisition [Line Items]
Minimum coverage period of product warranty from the date of shipment	1 year
Accrued warranty obligations	$ 17,617,000	$ 15,362,000	$ 13,001,000
Changes in Product Warranty Liability
Accrued warranty obligations, as of the beginning of the period	17,617,000	15,362,000
Provision for warranty obligations	1,106,000	1,083,000
Charges incurred	(1,830,000)	(1,461,000)
Warranty settlement (see below)	(3,892,000)	0
Accrued warranty obligations, as of the end of the period	13,001,000	$ 14,984,000
TeleCommunication Systems Inc. | TCS 911 call handling software solution
Business Acquisition [Line Items]
Accrued warranty obligations	9,909,000		5,546,000
Changes in Product Warranty Liability
Accrued warranty obligations, as of the beginning of the period	9,909,000
Accrued warranty obligations, as of the end of the period	$ 5,546,000
TeleCommunication Systems Inc. | TCS 911 call handling software solution | Full and final warranty settlement with AT&T
Business Acquisition [Line Items]
Number of monthly credits issued | credit	36
Amount of monthly credit			153,000
Present value of monthly credits			4,721,000
TeleCommunication Systems Inc. | TCS 911 call handling software solution | Full and final warranty settlement with AT&T | Accounts Payable and Accrued Liabilities
Business Acquisition [Line Items]
Present value of monthly credits			1,489,000
TeleCommunication Systems Inc. | TCS 911 call handling software solution | Full and final warranty settlement with AT&T | Other Noncurrent Liabilities
Business Acquisition [Line Items]
Present value of monthly credits			$ 3,232,000
TeleCommunication Systems Inc. | TCS 911 call handling software solution | Full and final warranty settlement with AT&T | Cost of sales
Business Acquisition [Line Items]
A benefit in connection with favorable settlement	$ 660,000