DEFERRED REVENUE (SCHEDULE OF CHANGES IN DEFERRED REVENUE) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
DEFERRED REVENUE AND COSTS [ABSTRACT]
Deferred Revenue, Beginning Balance	$ 62,589
Deferred Revenue, Additions	136,852
Amortization	(142,051)
Deferred Revenue, Ending Balance	$ 57,390