LICENSE, SETTLEMENT AND RELEASE AGREEMENT (Details) $ in Thousands												3 Months Ended		6 Months Ended
	Apr. 30, 2019 USD ($) installment_payment	Mar. 28, 2019 USD ($)	Jan. 28, 2019 USD ($)	Mar. 29, 2018 USD ($)	Mar. 19, 2018 USD ($)	Feb. 28, 2018 USD ($)	Feb. 01, 2018 USD ($)	May 31, 2017 USD ($)	Apr. 21, 2017 USD ($)	Mar. 31, 2017 USD ($)	Mar. 30, 2017 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jan. 31, 2019 USD ($)
Finite-Lived Intangible Assets [Line Items]
License revenue												$ 7,250	$ 17,300	$ 7,250	$ 82,300
Licensing Agreements | Zscaler
Finite-Lived Intangible Assets [Line Items]
Settlement, amount awarded from other party	$ 7,250
Payment period	5 days
Percentage of gross revenues	8.00%
Number of quarterly installments | installment_payment	4
Licensing Agreements | Symantec Corp
Finite-Lived Intangible Assets [Line Items]
Settlement, amount awarded from other party					$ 65,000
Payment period						20 days
Payable period of agreement						4 years
Licensing Agreements | EU Licensee
Finite-Lived Intangible Assets [Line Items]
Settlement, amount awarded from other party									$ 4,900
Payment period									10 days
Accounts receivable																	$ 1,300
Licensing Agreements | Sophos Group
Finite-Lived Intangible Assets [Line Items]
Settlement, amount awarded from other party											$ 2,500
Cash received from license agreement										$ 15,000
Maximum | Licensing Agreements | Symantec Corp
Finite-Lived Intangible Assets [Line Items]
Additional license fees						$ 45,000
License | Licensing Agreements | Symantec Corp
Finite-Lived Intangible Assets [Line Items]
License revenue															$ 65,000
License | Licensing Agreements | EU Licensee
Finite-Lived Intangible Assets [Line Items]
License revenue			$ 1,300				$ 1,300	$ 2,300								$ 2,300
License | Licensing Agreements | Sophos Group
Finite-Lived Intangible Assets [Line Items]
License revenue		$ 1,250		$ 1,250						$ 15,000