OTHER INCOME - Summary of Other Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
OTHER (EXPENSE) INCOME
COVID Relief	$ 2,691		$ 2,691
Unrealized and realized (loss) gain on investments (note 6)	279	$ 925	(619)	$ 1,752
Foreign currency gain (loss)	60	(537)	1,868	(374)
Other income, net	14	75	41	132
Total other (expense) income	$ 3,044	$ 463	$ 3,981	$ 1,510