GOODWILL AND OTHER INTANGIBLE ASSETS - Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Goodwill - net book value, begging of period	$ 1,425,542	$ 632,469	$ 627,392
Acquisitions	3,068	793,073	5,077
Goodwill - net book value, end of period	$ 1,428,610	$ 1,425,542	$ 632,469