Revenues and Gain on Sale of Rights in Wireless Spectrum (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jul. 31, 2014	Jul. 31, 2013
Summary of revenues and gain on sale
Revenues	$ 4,796	$ 1,130
Straight Path Spectrum [Member]
Summary of revenues and gain on sale
Revenues	424	525
Straight Path Spectrum [Member] | Telepacific Communications [Member]
Summary of revenues and gain on sale
Revenues	165	165
Straight Path Spectrum [Member] | AT&T[Member]
Summary of revenues and gain on sale
Revenues	114	134
Straight Path Spectrum [Member] | UNSI [Member]
Summary of revenues and gain on sale
Revenues	$ 53