Stock-Based Compensation - Expense (Details) - USD ($) $ in Thousands	12 Months Ended
Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
Income statement components of stock-based compensation expense recognized in Consolidated Statements of Income
Stock-based compensation before income taxes	$ 9,615	$ 8,844	$ 8,361
Total unrecognized stock-based compensation cost (in dollars)	$ 12,102
Remaining weighted average period for unrecognized compensation cost	18 months
Cost of sales
Income statement components of stock-based compensation expense recognized in Consolidated Statements of Income
Stock-based compensation before income taxes	$ 663	371	438
Selling
Income statement components of stock-based compensation expense recognized in Consolidated Statements of Income
Stock-based compensation before income taxes	1,458	1,582	929
General and administrative
Income statement components of stock-based compensation expense recognized in Consolidated Statements of Income
Stock-based compensation before income taxes	7,292	6,774	6,881
Research and development
Income statement components of stock-based compensation expense recognized in Consolidated Statements of Income
Stock-based compensation before income taxes	202	117	113
Total operating expenses
Income statement components of stock-based compensation expense recognized in Consolidated Statements of Income
Stock-based compensation before income taxes	$ 8,952	$ 8,473	$ 7,923

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Unrecognized cost of unvested share-based compensation awards.

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