INCOME TAXES - Deferred Income Tax Recovery (Expense) and Net Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deferred income tax recovery (expense)
United States	$ 515	$ (442)	$ 215
Foreign	3,234	25,002	106,955
Deferred tax recovery	3,749	24,560	107,170
Net income (loss) before tax:
United States	(13,959)	(19,935)	(21,436)
Foreign	31,265	(25,075)	(397,677)
Income (loss) before income taxes	$ 17,306	$ (45,010)	$ (419,113)