ACQUIRED INTANGIBLE ASSETS, NET (Summary of Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Impairment of intangible assets	$ (8,000)	$ (7,200)	$ (15,200)	$ 0
Acquired intangible assets, net	$ 23,800		$ 23,800		$ 39,000
Intangible Asset, discount rate	15.50%	17.50%	15.50%
Intangible Asset, royalty rate	4.00%	5.00%	4.00%
Intangible Asset, royalty rate	4.00%	5.00%	4.00%
Intangible Asset, discount rate	15.50%	17.50%	15.50%