Goodwill and Intangible Assets (Detail Textuals) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Schedule Of Goodwill And Intangible Assets [Line Items]
Goodwill	$ 2,261,002	$ 2,278,512
Goodwill Impairment	3,400
Reclassification from indefinite lived intangible assets to definite lived assets	1,433,180	$ 1,717,262
Cloud Tv Reporting Unit
Schedule Of Goodwill And Intangible Assets [Line Items]
Goodwill Impairment	3,400
Cloud Tv Reporting Unit | Non-controlling Interest
Schedule Of Goodwill And Intangible Assets [Line Items]
Goodwill Impairment	1,200
In-process R&D
Schedule Of Goodwill And Intangible Assets [Line Items]
Reclassification from indefinite lived intangible assets to definite lived assets	4,100
Ruckus Wireless and ICX Switch business (Ruckus Networks)
Schedule Of Goodwill And Intangible Assets [Line Items]
Goodwill	310,812
Acquired intangible assets	$ 494,700