Litigation (Details) - Positive Outcome of Litigation [Member]	Oct. 20, 2017	Oct. 16, 2017 USD ($)	Oct. 13, 2017 USD ($)	Sep. 29, 2017 USD ($)	Sep. 30, 2016 USD ($) Patent	Jul. 29, 2016 Case	Feb. 04, 2016 USD ($) Patent	Mar. 30, 2015 Action	Feb. 26, 2013 USD ($)	Nov. 06, 2012 USD ($) Patent	Sep. 30, 2017 Lawsuit
Gain Contingencies [Line Items]
Number of intellectual property infringement lawsuits pending | Lawsuit											11
VirnetX Inc. v. Apple, Inc. (Case 6:12-CV-00855-LED) [Member]
Gain Contingencies [Line Items]
Number of civil actions consolidated by court | Action								2
Amount of damages awarded in patent infringement case							$ 625,600,000
Number of patents allegedly infringed upon by Apple, Inc. | Patent							4
Number of cases ordered to be retried by court | Case						2
VirnetX Inc. v. Cisco Systems, Inc. et al. (Case 6:10-CV-00417-LED) ("Apple I") [Member]
Gain Contingencies [Line Items]
Number of civil actions consolidated by court | Action								2
Amount of damages awarded in patent infringement case				$ 343,699,000	$ 302,400,000					$ 368,000,000
Number of patents allegedly infringed upon by Apple, Inc. | Patent					4					4
Number of cases ordered to be retried by court | Case						2
Amount of interest payment awarded up to final judgment, per day									$ 34,000
Amount of damage infringement payment awarded up to final judgment, per day									$ 330,000
Percentage of enhanced damages awarded during the willfulness period.				50.00%
Enhanced damages				$ 41,271,000
VirnetX Inc. v. Cisco Systems, Inc. et al. (Case 6:10-CV-00417-LED) ("Apple I") [Member] | Subsequent Event [Member]
Gain Contingencies [Line Items]
Amount of damages awarded in patent infringement case		$ 439,727,000	$ 439,727,000
Royalty rate per device used in calculating infringement damages		$ 1.20
Additional amount granted in agreed bill of costs, attorney fees, and prejudgment interest			$ (96,028,000)
Period within which an entity is to inform court regarding its wish to participate in trial	30 days
VirnetX Inc. v. Cisco Systems, Inc. et al. (Case 6:10-CV-00417-LED) ("Apple I") [Member] | Minimum [Member]
Gain Contingencies [Line Items]
Royalty rate per device used in calculating infringement damages				1.20
VirnetX Inc. v. Cisco Systems, Inc. et al. (Case 6:10-CV-00417-LED) ("Apple I") [Member] | Maximum [Member]
Gain Contingencies [Line Items]
Royalty rate per device used in calculating infringement damages				$ 1.80
VirnetX Inc. v. Apple, Inc. (Case 6:12-CV-00855-LED) ("Apple II") [Member]
Gain Contingencies [Line Items]
Number of civil actions consolidated by court | Action								2
Number of patents allegedly infringed upon by Apple, Inc. | Patent										4
Number of cases ordered to be retried by court | Case						2