Business Segment Information (Details Textual) - Segments	1 Months Ended		3 Months Ended	21 Months Ended
	Oct. 24, 2017	Jan. 31, 2016	Oct. 31, 2017	Oct. 23, 2017
Business Segment Information (Textual)
Reportable segments			2
Straight Path Ventures [Member] | Gigabit Mobility Lab [Member]
Business Segment Information (Textual)
Percentage of employment expenses	100.00%			100.00%
Straight Path Ventures [Member] | Chief Technology Officer [Member]
Business Segment Information (Textual)
Percentage of employment expenses				60.00%
Straight Path Ventures [Member] | One Employee [Member]
Business Segment Information (Textual)
Percentage of employment expenses				80.00%
Straight Path Ventures [Member] | One Other Employee [Member]
Business Segment Information (Textual)
Percentage of employment expenses	80.00%
Straight Path IP Group [Member]
Business Segment Information (Textual)
Percentage of employment expenses	20.00%	80.00%		20.00%
Straight Path IP Group [Member] | Chief Technology Officer [Member]
Business Segment Information (Textual)
Percentage of employment expenses				20.00%
Straight Path Spectrum [Member]
Business Segment Information (Textual)
Percentage of employment expenses		20.00%		80.00%
Straight Path Spectrum [Member] | General and Administrative Expense [Member]
Business Segment Information (Textual)
Percentage of employment expenses	100.00%
Straight Path Spectrum [Member] | Chief Technology Officer [Member]
Business Segment Information (Textual)
Percentage of employment expenses	20.00%			20.00%
Straight Path Spectrum [Member] | One Employee [Member]
Business Segment Information (Textual)
Percentage of employment expenses				20.00%
Straight Path Spectrum [Member] | Other Employees [Member]
Business Segment Information (Textual)
Percentage of employment expenses	100.00%			100.00%