Net Gains and Losses Related to Derivative Contracts (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Apr. 30, 2018	Apr. 30, 2018
Derivative [Line Items]
Unrealized gains (losses) on derivatives not designated as hedging instruments	$ (188)	$ (188)
Realized gains (losses) on derivatives not designated as hedging instruments	$ (57)	$ (57)

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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