GOODWILL AND INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 02, 2015
Intangible Assets, Net[Abstract]
Total intangible assets, Gross		$ 59,911	$ 62,911
Accumulated amortization		(34,492)	(31,409)
Total Finite Lived Intangible Assets, Net	[1]	19,468
Total Intangible Assets, Net		25,419	31,502
Amortization of intangibles		$ 6,083	6,663	$ 7,039
Cambridge Semiconductor Limited [Member]
Intangible Assets and Goodwill [Line Items]
Intangible assets					$ 9,020
Minimum [Member]
Intangible Assets and Goodwill [Line Items]
Useful life (in years)		2 years
Maximum [Member]
Intangible Assets and Goodwill [Line Items]
Useful life (in years)		12 years
Developed technology
Intangible Assets, Net[Abstract]
Finite-Lived Intangible Assets, Gross		$ 33,270	33,270
Accumulated amortization		(19,211)	(15,455)
Total Finite Lived Intangible Assets, Net		$ 14,059	17,815
Developed technology | Cambridge Semiconductor Limited [Member]
Intangible Assets and Goodwill [Line Items]
Intangible assets					6,600
Developed technology | Minimum [Member] | Cambridge Semiconductor Limited [Member]
Intangible Assets and Goodwill [Line Items]
Useful life (in years)		3 years
Developed technology | Maximum [Member] | Cambridge Semiconductor Limited [Member]
Intangible Assets and Goodwill [Line Items]
Useful life (in years)		7 years
Customer relationships [Member]
Intangible Assets, Net[Abstract]
Finite-Lived Intangible Assets, Gross		$ 20,030	20,030
Accumulated amortization		(14,621)	(12,474)
Total Finite Lived Intangible Assets, Net		$ 5,409	7,556
Customer relationships [Member] | Cambridge Semiconductor Limited [Member]
Intangible Assets and Goodwill [Line Items]
Intangible assets					$ 2,420
Useful life (in years)		5 years
Technology licenses [Member]
Intangible Assets, Net[Abstract]
Finite-Lived Intangible Assets, Gross		$ 0	3,000
Accumulated amortization		0	(3,000)
Total Finite Lived Intangible Assets, Net		0	0
Leases, Acquired-in-Place [Member]
Intangible Assets, Net[Abstract]
Finite-Lived Intangible Assets, Gross		660	660
Accumulated amortization		(660)	(480)
Total Finite Lived Intangible Assets, Net		0	180
Domain name
Intangible Assets, Net[Abstract]
Indefinite-lived intangible assets		1,261	1,261
In-process research and development
Intangible Assets, Net[Abstract]
Finite-Lived Intangible Assets, Gross		4,690	4,690
Total Finite Lived Intangible Assets, Net		4,690	$ 4,690
In-process research and development | Early Stage Research And Developement Company [Member]
Intangible Assets and Goodwill [Line Items]
Finite-lived intangible assets		$ 4,690

[1] The total above excludes $4.7 million of in-process R&D which will be amortized upon completion of development over the estimated useful life of the technology.