Spin-Off of Rafael Holdings, Inc. and Investment in Rafael Pharmaceuticals, Inc. (Details) - Rafael Pharma [Member] - USD ($) $ in Thousands	Jan. 31, 2018	Jul. 31, 2017
Schedule of consolidated balance sheets
Series D Note (at fair value)	$ 6,300	$ 6,300
Warrants (at cost)	5,400	5,400
Right to receive additional shares (at cost)		400
Total investment in Rafael Pharma	$ 11,700	$ 12,100

Value of outstanding derivative securities that permit the holder the right to purchase securities (usually equity) from the issuer at a specified price.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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