LONG-TERM DEBT, NET - Schedule of Interest Expense, Exchangeable Notes (Details) - Senior Notes - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
2022 Exchangeable Notes
Debt Instrument [Line Items]
Contractual interest expense	$ 1,132	$ 1,132	$ 3,396	$ 3,396
Amortization of original issue discount	3,575	3,006	10,564	9,765
Amortization of debt issuance costs	885	375	2,615	2,117
Total interest expense recognized	5,592	4,513	16,575	15,278
2026 Exchangeable Notes
Debt Instrument [Line Items]
Contractual interest expense	1,257	1,258	3,773	1,705
Amortization of original issue discount	4,378	4,109	12,830	5,608
Amortization of debt issuance costs	332	294	972	425
Total interest expense recognized	5,967	5,661	17,575	7,738
2030 Exchangeable Notes
Debt Instrument [Line Items]
Contractual interest expense	2,875	2,875	8,625	3,897
Amortization of original issue discount	3,369	3,124	9,888	4,270
Amortization of debt issuance costs	183	148	537	233
Total interest expense recognized	$ 6,427	$ 6,147	$ 19,050	$ 8,400