FAIR VALUE MEASUREMENTS - Schedule of fair value measurement valuation (Details) - Level 3 $ in Thousands	Dec. 31, 2020 USD ($)
Fair Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration on acquisition date	$ 8,249
Option pricing model | Weighted Average | Operating results growth rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration, measurement input	0.048
Option pricing model | Weighted Average | Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration, measurement input	0.068