GOODWILL AND INTANGIBLE ASSETS (Schedule of Goodwill) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($)
Goodwill [Roll Forward]
Balance, beginning of period	$ 1,001,889
Currency Translation	(30,278)
Balance, end of period	971,611
U.S.
Goodwill [Roll Forward]
Balance, beginning of period	41,936
Currency Translation	0
Balance, end of period	41,936
U.K. and Europe
Goodwill [Roll Forward]
Balance, beginning of period	834,346
Currency Translation	(30,278)
Balance, end of period	804,068
Mexico
Goodwill [Roll Forward]
Balance, beginning of period	125,607
Currency Translation	0
Balance, end of period	$ 125,607