Discontinued Operations - Summary Financial Data of Discontinued Operations (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues		$ 1,130	$ 46,349
(Loss) income before income taxes		(4,621)	7,471
Net (loss) income		(4,634)	5,851
Straight Path [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues		1,130	553
(Loss) income before income taxes		(4,621)	4,862
Net (loss) income		(4,634)	4,836
Genie [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues			45,796
(Loss) income before income taxes			2,609
Net (loss) income			$ 1,015