Description of Business and Summary of Significant Accounting Policies (Details 2) - USD ($) $ in Thousands		12 Months Ended
		Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Reserves deducted from accounts receivable:
Allowance for doubtful accounts, Balance at beginning of year		$ 5,358	$ 5,207	$ 4,818
Allowance for doubtful accounts, Additions charged to costs and expenses		2,028	2,199	686
Allowance for doubtful accounts, Deductions	[1]	(1,942)	(2,048)	(297)
Allowance for doubtful accounts, Balance at end of year		$ 5,444	$ 5,358	$ 5,207

[1] Primarily uncollectible accounts written off, net of recoveries.