Business Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2016	Apr. 30, 2015
Summary of operating results for the business segments
Revenues	$ 219	$ 2,867	$ 2,034	$ 10,471
Income (loss) from operations	(1,902)	199	(5,214)	1,649
Straight Path Spectrum [Member]
Summary of operating results for the business segments
Revenues	122	99	339	288
Income (loss) from operations	(1,308)	(353)	(2,484)	(1,062)
Straight Path IP [Member]
Summary of operating results for the business segments
Revenues	97	2,768	1,695	10,183
Income (loss) from operations	$ (160)	$ 552	$ (2,173)	$ 2,711
Straight Path Ventures [Member]
Summary of operating results for the business segments
Revenues
Income (loss) from operations	$ (434)		$ (557)