Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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Name:	us-gaap_SeveranceCosts1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Severance Expense (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
Severance Expense (Details) - USD ($) $ in Thousands	Jul. 31, 2018	Apr. 30, 2018	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
Severance Expense (Textual)
Severance expense	$ 300	$ 3,700	$ 4,630		$ 6,510
Accrued severance	100		100	$ 300
Workforce reduction [Member]
Severance Expense (Textual)
Severance expense			3,900		6,300
Accrued severance	$ 2,100		2,100
Unrelated to workforce reduction [Member]
Severance Expense (Textual)
Severance expense			$ 700		$ 200