FAIR VALUE ACCOUNTING - Fair Value Measurements, Recurring and Nonrecurring (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible Debentures (Note 11)	$ 0	$ 15,880
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	654	1,107
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liabilities (Note 12)	0	(662)
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	654	1,107
Time Deposits	630	1,460
Short-term Investments	4,208	25,601
Warrant liabilities (Note 12)	(2,791)	(6,283)
Convertible Debentures (Note 11)	16,866	15,880
Fair Value, Net Asset (Liability)	(14,165)	6,005
Fair Value, Measurements, Recurring [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	654	1,107
Time Deposits	630	1,460
Short-term Investments	0	0
Warrant liabilities (Note 12)	(2,791)	(5,621)
Convertible Debentures (Note 11)	16,866	15,880
Fair Value, Net Asset (Liability)	(18,373)	(18,934)
Fair Value, Measurements, Recurring [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	0	0
Time Deposits	0	0
Short-term Investments	4,208	25,601
Warrant liabilities (Note 12)	0	0
Convertible Debentures (Note 11)	0	0
Fair Value, Net Asset (Liability)	4,208	25,601
Fair Value, Measurements, Recurring [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	0	0
Time Deposits	0	0
Short-term Investments	0	0
Warrant liabilities (Note 12)	0	(662)
Convertible Debentures (Note 11)	0	0
Fair Value, Net Asset (Liability)	$ 0	$ (662)