Business Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2016	Oct. 31, 2015
Summary of operating results for the business segments
Revenues	$ 159	$ 1,703
Income (loss) from operations	(4,277)	(691)
Straight Path Spectrum [Member]
Summary of operating results for the business segments
Revenues	159	105
Income (loss) from operations	(2,985)	(334)
Straight Path IP Group [Member]
Summary of operating results for the business segments
Revenues		1,598
Income (loss) from operations	(875)	(357)
Straight Path Ventures [Member]
Summary of operating results for the business segments
Revenues
Income (loss) from operations	$ (417)