Financial Assets and Liabilities Measured at Fair Value and Related Valuation Inputs (Parenthetical) (Detail) - USD ($) $ in Thousands		Jan. 31, 2018	Jul. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure		$ 171,048	$ 160,724
Cash and Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	[1]	118,223	103,637
Cash held in operating accounts | Cash and Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure		$ 117,700	$ 103,500

[1] Cash and cash equivalents as of January 31, 2018 and July 31, 2017 includes cash held in operating accounts of approximately $117.7 million and $103.5 million, respectively, that are not subject to fair value measurements. For purposes of this disclosure, they are included as having Level 1 inputs.