REVENUES - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Liabilities:
Contract liabilities, net (current)	$ 187,084	$ 193,405
Contract liabilities, net (noncurrent)	42,556	35,272
Obtain Contract
Assets:
Capitalized costs, net	232,030	226,945
Fulfill Contract
Assets:
Capitalized costs, net	$ 52,573	$ 38,150