INCOME TAXES - Expense (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Domestic and foreign loss before income taxes:
United States	$ (80,598)	$ (42,456)
Foreign	(430)	(818)
Total losses before taxes	(81,028)	(43,274)
Income tax expense
Current income taxes	0	0
Deferred income taxes	$ 0	$ 0

Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.

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Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

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

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