Stock-Based Compensation - Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Income statement components of stock-based compensation expense recognized in Consolidated Statements of Income
Stock-based compensation expense	$ 12,076	$ 15,562	$ 9,615
Maximum share attainment as a percentage of initially granted shares	200.00%
Total unrecognized stock-based compensation cost	$ 18,125
Remaining weighted average period for unrecognized compensation cost	13 months
Cost of sales
Income statement components of stock-based compensation expense recognized in Consolidated Statements of Income
Stock-based compensation expense	$ 1,255	1,010	663
Selling
Income statement components of stock-based compensation expense recognized in Consolidated Statements of Income
Stock-based compensation expense	2,606	2,428	1,458
General and administrative
Income statement components of stock-based compensation expense recognized in Consolidated Statements of Income
Stock-based compensation expense	7,803	11,828	7,292
Research and development
Income statement components of stock-based compensation expense recognized in Consolidated Statements of Income
Stock-based compensation expense	412	296	202
Total operating expenses
Income statement components of stock-based compensation expense recognized in Consolidated Statements of Income
Stock-based compensation expense	$ 10,821	$ 14,552	$ 8,952