REVENUE - Contract Balances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Contract with Customer, Asset and Liability [Abstract]
Receivables, included in “Accounts receivable net of allowance for doubtful accounts”	$ 376,504	$ 330,983
Unearned revenue - current	9,894	22,692
Unearned revenue - noncurrent	2,113	$ 1,138
Change in Contract with Customer, Liability [Abstract]
Beginning balance	23,830
Revenue recognized during the period that was included in the beginning balance of contract liabilities	(23,830)
Additional amounts recognized during period	12,007
Ending balance	$ 12,007