GOODWILL AND INTANGIBLE ASSETS - SCHEDULE OF CHANGES IN CARRYING VALUE OF GOODWILL BY REPORTABLE SEGMENT (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill, gross			$ 2,163,451
Accumulated impairment loss			(362,348)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 1,988,215	$ 1,985,955	1,801,103
Acquired during the period		178,179
Goodwill, Purchase Accounting Adjustments	825	1,061
Foreign Currency Translation	1,435	5,612
Goodwill, ending balance	1,988,215	1,985,955
Operating Segments | North America
Goodwill [Line Items]
Goodwill, gross			1,787,818
Accumulated impairment loss			(4,973)
Goodwill [Roll Forward]
Goodwill, beginning balance	1,970,445	1,967,466	1,782,845
Acquired during the period		178,179
Goodwill, Purchase Accounting Adjustments	825	1,061
Foreign Currency Translation	2,154	5,381
Goodwill, ending balance	1,970,445	1,967,466
Operating Segments | International and Other
Goodwill [Line Items]
Goodwill, gross			375,633
Accumulated impairment loss			(357,375)
Goodwill [Roll Forward]
Goodwill, beginning balance	17,770	18,489	$ 18,258
Acquired during the period		0
Goodwill, Purchase Accounting Adjustments	0	0
Foreign Currency Translation	(719)	231
Goodwill, ending balance	$ 17,770	$ 18,489