REVENUES - Contract With Customer Asset And Liability (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
REVENUES
Contracts liability at the beginning of the period	$ 42,895	$ 25,015
Additions during the period	22,151	34,929
Revenue recognized during the period	(24,848)	(16,665)
Contracts liability at the end of the period	$ 40,198	$ 43,279