SEGMENT REPORTING - Schedule of Segment Reporting, Goodwill and Assets (Details) - USD ($) $ in Thousands	Apr. 01, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Goodwill	$ 1,033,126	$ 1,001,889
Assets	6,397,635	6,248,652
Elimination
Segment Reporting Information [Line Items]
Assets	(1,558,516)	(1,357,672)
Elimination | U.S. Segment's Investment In The Mexico Segment
Segment Reporting Information [Line Items]
Assets	191,700	191,700
Elimination | Receivables Between U.S. And Mexico Segments
Segment Reporting Information [Line Items]
Assets	111,100	111,100
Elimination | U.S. Segment's Investment In The U.K. And Europe Segment
Segment Reporting Information [Line Items]
Assets	1,300,000	1,100,000
U.S.
Segment Reporting Information [Line Items]
Goodwill	41,936	41,936
U.S. | Reportable Geographical Components
Segment Reporting Information [Line Items]
Goodwill	41,936	41,936
Assets	4,784,793	4,444,918
U.K. and Europe
Segment Reporting Information [Line Items]
Goodwill	865,583	834,346
U.K. and Europe | Reportable Geographical Components
Segment Reporting Information [Line Items]
Goodwill	865,583	834,346
Assets	2,202,251	2,226,895
Mexico
Segment Reporting Information [Line Items]
Goodwill	125,607	125,607
Mexico | Reportable Geographical Components
Segment Reporting Information [Line Items]
Goodwill	125,607	125,607
Assets	$ 969,107	$ 934,511