Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended
Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2015	Jan. 31, 2014
Statements of Operations [Abstract]
Revenues	$ 2,781us-gaap_Revenues	$ 453us-gaap_Revenues	$ 7,604us-gaap_Revenues	$ 580us-gaap_Revenues
Costs and expenses:
Direct cost of revenues	1,338us-gaap_CostOfRevenue	283us-gaap_CostOfRevenue	3,446us-gaap_CostOfRevenue	311us-gaap_CostOfRevenue
Selling, general and administrative	1,605	1,042	2,708	1,611
Total costs and expenses	2,943us-gaap_CostsAndExpenses	1,325us-gaap_CostsAndExpenses	6,154us-gaap_CostsAndExpenses	1,922us-gaap_CostsAndExpenses
Income (loss) from operations	(162)us-gaap_OperatingIncomeLoss	(872)us-gaap_OperatingIncomeLoss	1,450us-gaap_OperatingIncomeLoss	(1,342)us-gaap_OperatingIncomeLoss
Other income:
Interest income	9us-gaap_InterestIncomeOther	4us-gaap_InterestIncomeOther	18us-gaap_InterestIncomeOther	7us-gaap_InterestIncomeOther
Other income			23us-gaap_OtherIncome
Income from IDT Corporation payments of liabilities				50strp_IncomeFromPaymentsOfLiabilities
Total other income	9us-gaap_InterestAndOtherIncome	4us-gaap_InterestAndOtherIncome	41us-gaap_InterestAndOtherIncome	57us-gaap_InterestAndOtherIncome
Income (loss) before income taxes	(153)	(868)	1,491	(1,285)
Provision for income taxes	(100)us-gaap_IncomeTaxExpenseBenefit		(855)us-gaap_IncomeTaxExpenseBenefit
Net income (loss)	(253)us-gaap_ProfitLoss	(868)us-gaap_ProfitLoss	636us-gaap_ProfitLoss	(1,285)us-gaap_ProfitLoss
Net (income) loss attributable to noncontrolling interests	(24)	141	(207)	167
Net income (loss) attributable to Straight Path Communications Inc.	$ (277)us-gaap_NetIncomeLoss	$ (727)us-gaap_NetIncomeLoss	$ 429us-gaap_NetIncomeLoss	$ (1,118)us-gaap_NetIncomeLoss
Earnings (loss) per share attributable to Straight Path Communications Inc. stockholders:
Basic	$ (0.02)us-gaap_EarningsPerShareBasic	$ (0.07)us-gaap_EarningsPerShareBasic	$ 0.04us-gaap_EarningsPerShareBasic	$ (0.11)us-gaap_EarningsPerShareBasic
Diluted	$ (0.02)us-gaap_EarningsPerShareDiluted	$ (0.07)us-gaap_EarningsPerShareDiluted	$ 0.04us-gaap_EarningsPerShareDiluted	$ (0.11)us-gaap_EarningsPerShareDiluted
Weighted-average number of shares used in calculation of earnings (loss) per share:
Basic	11,420	10,784	11,409	10,646
Diluted	11,420	10,784	11,837	10,646

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