Business Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2014	Jan. 31, 2013	Jul. 31, 2012
Summary of operating results for the business segments
Revenues	$ 453	$ 229	$ 580	$ 697
Loss from operations	(872)	(408)	(1,342)	(1,882)
Gain on sale of rights in wireless spectrum		150		150
Straight Path Spectrum [Member]
Summary of operating results for the business segments
Revenues	109	136	216	277
Loss from operations	(175)	116	(235)	80
Gain on sale of rights in wireless spectrum		150		150	5,300
Straight Path IP [Member]
Summary of operating results for the business segments
Revenues	344	93	364	420
Loss from operations	(697)	(524)	(1,107)	(1,962)
Gain on sale of rights in wireless spectrum