BUSINESS COMBINATIONS - Pro forma summary of financials (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Business Acquisition, Pro Forma Information [Abstract]
Net revenues	$ 304,464	$ 176,261	$ 545,665	$ 473,834
Net income (loss)	$ 1,299	$ (55,900)	$ (20,613)	$ (66,474)
Net income (loss) per common share - basic (in dollars per share)	$ 0.01	$ (0.41)	$ (0.15)	$ (0.49)
Net income (loss) per common share - diluted (in dollars per share)	$ 0.01	$ (0.41)	$ (0.15)	$ (0.49)
Weighted shares outstanding basic (in shares)	135,808,435	134,804,963	135,784,286	134,785,749
Weighted shares outstanding diluted (in shares)	137,786,768	134,804,963	135,784,286	134,785,749