Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Statements of Operations [Abstract]
Revenues	$ 658	$ 2,156	$ 13,240
Costs and expenses:
Direct cost of revenues	115	933	6,043
Research and development	582	1,286
Selling, general and administrative (related party of $1,613, $596 and $420)	20,772	9,024	6,931
Total costs and expenses	21,469	11,243	12,974
Income (loss) from operations before items listed below	(20,811)	(9,087)	266
Civil penalty - FCC consent decree	15,000
Settlement of litigation	7,200
Income (loss) from operations	(43,011)	(9,087)	266
Other income (expense):
Interest expense, including amortization of debt discounts	(2,688)
Interest income	30	39	38
Other income	22	398	334
Total other income (expense)	(2,636)	437	372
Income (loss) before income taxes	(45,647)	(8,650)	638
Income tax benefits (provision for income taxes)	(13)	4	(2,714)
Net loss	(45,660)	(8,646)	(2,076)
Net loss attributable to noncontrolling interests	1,013	349	111
Net loss attributable to Straight Path Communications Inc.	$ (44,647)	$ (8,297)	$ (1,965)
Loss per share attributable to Straight Path Communications Inc. stockholders:
Basic and diluted	$ (3.67)	$ (0.70)	$ (0.17)
Weighted-average number of shares used in calculation of loss per share:
Basic and diluted	12,176	11,871	11,457