Contract Receivables, net, Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of period	$ 1,284	$ 2,044	$ 6,792
Provision for doubtful accounts during the period	182	813	682
Write-offs and recoveries of allowance recorded in prior periods	(676)	(943)	(5,430)
Reclassification of allowance (to) from noncurrent assets	214	(630)	0
Balance at end of period	$ 1,004	$ 1,284	$ 2,044