Other Operating Gains, Net- Additional Information (Detail) (USD $)	9 Months Ended
Apr. 30, 2014	Apr. 30, 2013
Other Operating Gains, Net (Textual)
Proceeds from insurance	$ 571,000
Gain on insurance claim	600,000
NEW JERSEY
Other Operating Gains, Net (Textual)
Proceeds from insurance	600,000
Former Chief Executive Officer of Straight Path Spectrum, Inc [Member]
Other Operating Gains, Net (Textual)
Loss on settlement of outstanding claims and disputes	$ (100,000)

The cash inflow from the amounts received by the insured under the terms of an insurance contract settlement. This element pertains only to insurance proceeds related to investments, for example fixed assets. It excludes insurance settlements classified as operating cash flows.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585

Name:	us-gaap_ProceedsFromInsuranceSettlementInvestingActivities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration