Commitments and Contingencies (Details Textual) $ in Thousands								1 Months Ended		3 Months Ended		9 Months Ended
	Oct. 11, 2017 USD ($)	Jul. 11, 2017 USD ($)	May 11, 2017	Apr. 11, 2017 USD ($)	Mar. 07, 2017 USD ($)	Feb. 11, 2017 USD ($)	Jan. 11, 2017 USD ($) Installments	Jun. 30, 2013 USD ($)	May 29, 2012	Apr. 30, 2017 USD ($)	Apr. 30, 2016 USD ($)	Apr. 30, 2017 USD ($)	Apr. 30, 2016 USD ($)
Commitments and Contingencies (Textual)
FCC Consent decree payable												$ 7,000
Payment of penalty												85,000
Additional payment										$ 85,000		85,000
Loan from lenders												$ 17,500
Description of legal settlement agreement					The Company will provide for a $2.25 million initial payment (the "Initial Payment") and a $7.2 million additional payment (the "Additional Payment"). The Initial Payment will be paid into an escrow account within 15 days following preliminary court approval of the settlement, and will be fully covered by insurance policies maintained by the Company. The Additional Payment of $7.2 million will be paid within 60 days after the closing of a transaction to sell the Company's spectrum licenses as specified in the Consent Decree with the Federal Communications Commission dated January 11, 2017 (the "Consent Decree"), or, in the event that the Company pays the non-transfer penalty specified in the Consent Decree, within 60 days after that payment is paid.
Settlement of initial payment					$ 2,250
Additional settlement payment					$ 7,200
Percentage of profit share									20.00%
Subsequent Event [Member]
Commitments and Contingencies (Textual)
Payment to consent decree, percentage			20.00%
Minimum [Member]
Commitments and Contingencies (Textual)
Recoverable contingency patents allegedly infringed, percentage												0.00%
Maximum [Member]
Commitments and Contingencies (Textual)
Recoverable contingency patents allegedly infringed, percentage												40.00%
Subsidiaries [Member] | Former Chief Executive Officer [Member]
Commitments and Contingencies (Textual)
Amount of maximum future payment for wireless spectrum licenses								$ 3,250
Amount incurred for obligation										$ 19,000	$ 6,000	$ 58,000	$ 36,000
Payments to be made from revenue, percentage								50.00%
Straight Path IP Group [Member]
Commitments and Contingencies (Textual)
Settlement of litigation, description												Straight Path IP Group generally pays law firms that represent it in litigation against alleged infringers of its intellectual property rights a percentage of the amounts recovered ranging from 0% to 40% depending on several factors.
Straight Path Spectrum'S Spectrum Licenses [Member]
Commitments and Contingencies (Textual)
Payments of initial civil penalty							$ 15,000
Installment value				$ 4,000		$ 4,000
Number of installments | Installments							4
Initial civil penalty							$ 15,000
Payments of additional penalty							85,000
Payment of two installments of initial civil penalty							$ 8,000
Straight Path Spectrum'S Spectrum Licenses [Member] | Subsequent Event [Member]
Commitments and Contingencies (Textual)
Installment value	$ 3,500	$ 3,500