Consolidated Comprehensive Statements of Operations (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Jul. 31, 2018	Jul. 31, 2017
Income Statement [Abstract]
Provision of Inventory		$ 99

Amount of loss from reductions in inventory due to subsequent measurement adjustments, including, but not limited to, physical deterioration, obsolescence, or changes in price levels.

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Name:	us-gaap_InventoryWriteDown
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration