FINANCIAL INSTRUMENTS Schedule of Other Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt and Equity Securities, FV-NI [Line Items]
Fair value / carrying value	$ 17,724	$ 16,384
Private investments and unlisted equity funds
Debt and Equity Securities, FV-NI [Line Items]
Cost	10,420	10,420
Unrealized gains	990	265
Unrealized losses	(276)	(4)
Fair value / carrying value	11,134	10,681
Investment accounted for under the equity method
Debt and Equity Securities, FV-NI [Line Items]
Fair value / carrying value	$ 6,590	$ 5,703