Investment in Rafael Pharmaceuticals, Inc. (Details) - Rafael [Member] - USD ($) $ in Thousands	Jul. 31, 2017	Jul. 31, 2016
Schedule of consolidated balance sheets
Convertible promissory note (at fair value)	$ 6,300	$ 2,000
Warrants (at cost)	5,400
Right to receive additional shares (at cost)	400
Total investment in Rafael	$ 12,100	$ 2,000