REVENUE RECOGNITION - NARRATIVE (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Contract with customer, asset, current	$ 10,821		$ 10,821	$ 11,623
Contract assets - long-term	3,172		3,172	$ 4,596
Increase (Decrease) in Contract with Customer, Asset			(2,200)
Royalty Revenue, Adjustment	2,000	$ (20)
Revenue, remaining performance obligation	24,000		24,000
Capitalized contract costs during the period	$ 100		$ 200