REVENUE RECOGNITION AND RECEIVABLES - Contract Acquisition Costs (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)
Contract Acquisition Costs
Amortization of contract acquisition cost	$ 500	$ 1,500
Prepayments and other current assets
Contract Acquisition Costs
Short-term contract acquisition costs	1,800	1,800
Other Assets
Contract Acquisition Costs
Long-term contract acquisition costs	$ 1,100	$ 1,100