Fair Value Measurements (Details Textual) - USD ($) $ in Millions	Apr. 30, 2018	Jul. 31, 2017
Fair Value Measurements (Textual)
Fair value of investments in hedge funds	$ 4.8	$ 8.6
Carrying value of investments	$ 3.0	$ 10.8

This item represents a financial instrument (as defined) for which it is not practicable to estimate fair value. Such disclosure may be for an individual financial instrument or a class of financial instruments.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 325
-SubTopic 20
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=75030709&loc=d3e39828-111592

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant