STOCK-BASED INCENTIVE COMPENSATION (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	May 31, 2021	May 03, 2018
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares authorized (in shares)					9,101,734
HC I Incentive Units
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based compensation expense	$ 2.5	$ 0.7	$ 3.7	$ 1.4
The 2018 Plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares authorized (in shares)					4,999,999	4,101,735