LONG-TERM DEBT, NET - Schedule of Interest Expense, Exchangeable Notes (Details) - Senior Notes - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
2022 Exchangeable Notes
Debt Instrument [Line Items]
Contractual interest expense	$ 1,132	$ 1,132	$ 2,264	$ 2,264
Amortization of original issue discount	3,535	3,396	6,989	6,759
Amortization of debt issuance costs	875	871	1,730	1,742
Total interest expense recognized	5,542	5,399	10,983	10,765
2026 Exchangeable Notes
Debt Instrument [Line Items]
Contractual interest expense	1,258	447	2,516	447
Amortization of original issue discount	4,235	1,499	8,452	1,499
Amortization of debt issuance costs	321	131	640	131
Total interest expense recognized	5,814	2,077	11,608	2,077
2030 Exchangeable Notes
Debt Instrument [Line Items]
Contractual interest expense	2,875	1,022	5,750	1,022
Amortization of original issue discount	3,273	1,146	6,519	1,146
Amortization of debt issuance costs	178	85	354	85
Total interest expense recognized	$ 6,326	$ 2,253	$ 12,623	$ 2,253