PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 174,849	$ 168,102
Accumulated depreciation and amortization	144,703	132,621
Property, plant and equipment, net	30,146	35,481
Capitalized Computer Software, Additions	1,300	5,100	$ 3,400
Capitalized Computer Software, Amortization	3,000	1,800	500
Annual depreciation and amortization	$ 15,200	13,700	$ 16,100
Internal Use Software [Domain]
Property, Plant and Equipment [Line Items]
Capitalized Computer Software, Useful Life	3 years
Computer and video equipment and software [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 120,853	116,751
Manufacturing tooling and testbeds [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	3,567	3,044
Office equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,958	4,942
Furniture, fixtures and other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	10,691	9,621
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 34,780	$ 33,744