Document and Entity Information - shares	3 Months Ended
	Oct. 31, 2017	Dec. 11, 2017
Entity Registrant Name	Straight Path Communications Inc.
Entity Central Index Key	0001574460
Trading Symbol	STRP
Amendment Flag	false
Current Fiscal Year End Date	--07-31
Document Type	10-Q
Document Period End Date	Oct. 31, 2017
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2018
Entity Filer Category	Accelerated Filer
Class A Common Stock
Entity Common Stock, Shares Outstanding		787,163
Class B Common Stock
Entity Common Stock, Shares Outstanding		11,980,664