SEGMENT INFORMATION (Revenues from External Customers and Operating Profit/(Loss) Before Unallocated Expenses) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Segment revenues	$ 632,775	$ 588,103	$ 551,587	$ 521,333	$ 504,931	$ 468,186	$ 445,647	$ 424,148	$ 2,293,798	$ 1,842,912	$ 1,450,448
Operating profit	$ 84,745	$ 80,565	$ 72,882	$ 64,658	$ 78,270	$ 64,560	$ 54,237	$ 48,697	302,850	245,764	172,946
North America Segment
Segment Reporting Information [Line Items]
Segment revenues									1,380,944	1,076,979	796,040
Operating profit									293,757	221,846	169,340
Europe Segment
Segment Reporting Information [Line Items]
Segment revenues									820,717	692,785	591,450
Operating profit									114,863	115,876	92,080
Russia Segment
Segment Reporting Information [Line Items]
Segment revenues									92,137	73,148	62,958
Operating profit									17,347	11,377	13,906
Operating Segments
Segment Reporting Information [Line Items]
Operating profit									$ 425,967	$ 349,099	$ 275,326