PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 190,732	$ 189,174
Accumulated depreciation and amortization	171,152	167,592
Property, Plant and Equipment, Net	19,580	21,582
Capitalized Computer Software, Additions	1,300	4,500
Capitalized Computer Software, Amortization	600	2,500
Annual depreciation and amortization	$ 9,200	11,900
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	$ 133,695	132,531
Manufacturing tooling and testbeds [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,209	3,635
Office equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,963	4,957
Furniture, fixtures and other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	10,425	10,458
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 37,440	$ 37,593