Business Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2016	Jan. 31, 2015
Summary of operating results for the business segments
Revenues	$ 112	$ 2,781	$ 1,815	$ 7,604
(Loss) income from operations	(2,621)	(162)	(3,312)	1,450
Straight Path Spectrum [Member]
Summary of operating results for the business segments
Revenues	112	93	217	189
(Loss) income from operations	$ (965)	(412)	(1,299)	(709)
Straight Path IP [Member]
Summary of operating results for the business segments
Revenues		2,688	1,598	7,415
(Loss) income from operations	$ (1,656)	$ 250	$ (2,013)	$ 2,159