GOODWILL AND INTANGIBLE ASSETS - Expected amortization of intangible assets (Details) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Expected amortization of intangible assets    
2021 $ 2,320  
2022 2,320  
2023 2,320  
2024 1,566  
Total $ 8,526 $ 12,256