Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
Statements of Operations [Abstract]
Revenues	$ 2,156	$ 13,240	$ 4,796
Costs and expenses:
Direct cost of revenues	933	6,043	2,487
Research and development	1,286
Selling, general and administrative	9,024	6,931	3,001
Total costs and expenses	11,243	12,974	5,488
(Loss) income from operations	(9,087)	266	(692)
Other income:
Interest income	39	38	22
Other income	398	334
Income from IDT Corporation payments of liabilities			386
Total other income	437	372	408
(Loss) income before income taxes	(8,650)	638	(284)
Income tax benefits (provision for income taxes)	4	(2,714)	2,353
Net (loss) income	(8,646)	(2,076)	2,069
Net loss (income) attributable to noncontrolling interests	349	111	(32)
Net (loss) income attributable to Straight Path Communications Inc.	$ (8,297)	$ (1,965)	$ 2,037
Earnings (loss) per share attributable to Straight Path Communications Inc. stockholders:
Basic	$ (0.70)	$ (0.17)	$ 0.19
Diluted	$ (0.70)	$ (0.17)	$ 0.18
Weighted-average number of shares used in calculation of earnings (loss) per share:
Basic	11,871	11,457	10,667
Diluted	11,871	11,457	11,267