INCOME TAXES - Income Tax (Provision) Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Domestic - Luxembourg	$ (3,576)	$ (10,957)	$ (9,889)
Deferred:
Domestic - Luxembourg	(5,033)	(307,339)	5,791
Income tax (provision) benefit	(8,609)	(318,296)	(4,098)
Domestic - Luxembourg
Current:
Domestic - Luxembourg	(2,158)	0	(275)
Deferred:
Domestic - Luxembourg	224	(308,657)	4,927
Foreign - U.S. federal
Current:
Foreign	4,992	187	(1,838)
Deferred:
Foreign	(2,808)	329	291
Foreign - U.S. state
Current:
Foreign	(322)	(174)	(336)
Deferred:
Foreign	(465)	341	(134)
Foreign - non-U.S.
Current:
Foreign	(6,088)	(10,970)	(7,440)
Deferred:
Foreign	$ (1,984)	$ 648	$ 707