INCOME TAXES - Components of Pre-tax Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Line Items]
Total pre-tax income (loss)	$ (20,952)	$ (107,500)	$ (33,693)
United States
Income Taxes [Line Items]
Pre-tax income (loss) U.S.	(35,529)	(27,468)	(15,977)
Canada
Income Taxes [Line Items]
Pre-tax income (loss) Canada	$ 14,577	$ (80,032)	$ (17,716)

Income Taxes [Line Items]

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The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations.

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The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile.

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Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

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