Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Statements of Operations [Abstract]
Selling, general and administrative related party	$ 1,613	$ 596	$ 420

Amount of selling, general and administrative expenses resulting from transactions, excluding transactions that are eliminated in consolidated or combined financial statements, with related party.

No definition available.

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