GOODWILL AND INTANGIBLE ASSETS - Goodwill by Reporting Unit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Goodwill
Balance at beginning of period	$ 894,709	$ 770,226
Additions	18,326	142,768
(Deductions)	(29,266)	(14,373)
Foreign Exchange Translation	191	(3,912)
Balance at end of period	883,960	894,709
North America
Goodwill
Balance at beginning of period	824,037	696,291
Additions	18,326	142,768
(Deductions)	(29,266)	(14,373)
Foreign Exchange Translation	320	(649)
Balance at end of period	813,417	824,037
Europe
Goodwill
Balance at beginning of period	70,672	73,935
Additions	0	0
(Deductions)	0	0
Foreign Exchange Translation	(129)	(3,263)
Balance at end of period	$ 70,543	$ 70,672