FAIR VALUE MEASUREMENT - Financial Instruments Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Jun. 18, 2020
Financial assets:
Stanley Brothers USA Holdings purchase option	$ 13,000	$ 0
Financial assets		0
Financial liabilities:
Warrant liabilities	0	4,304	$ 9,206
Level 1
Financial assets:
Stanley Brothers USA Holdings purchase option	0
Financial assets		0
Financial liabilities:
Warrant liabilities	0	0
Level 2
Financial assets:
Stanley Brothers USA Holdings purchase option	0
Financial assets		0
Financial liabilities:
Warrant liabilities	0	4,304
Level 3
Financial assets:
Stanley Brothers USA Holdings purchase option	13,000
Financial assets		0
Financial liabilities:
Warrant liabilities	$ 0	$ 0