LONG-TERM DEFERRED REVENUE LIABILITIES AND OTHER LONG-TERM LIABILITIES - Schedule of Deferred Revenue Liabilities and Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Long-term Purchase Commitment [Line Items]
Long-term deferred revenue liabilities	$ 36,826	$ 36,920
Total long-term deferred revenue liabilities and other long-term liabilities	73,655	73,749
WLR
Long-term Purchase Commitment [Line Items]
Long-term deferred revenue liabilities	13,061	13,061
WLWI
Long-term Purchase Commitment [Line Items]
Long-term deferred revenue liabilities	$ 23,768	$ 23,768