SEGMENT INFORMATION (Summary of Net Sales and Long-Lived Assets By Geographic Area) (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	Jan. 01, 2019
Net sales and long-lived asset information by geographic area
Net sales	$ 671,333	$ 701,278	$ 742,661	$ 744,460	$ 685,028	$ 665,775	$ 710,608	$ 703,350	$ 2,859,732	$ 2,764,761	$ 2,469,283
Plant, Property & Equipment	1,087,678				991,613				$ 1,087,678	$ 991,613	$ 867,906	$ 997,489
Customer Concentration Risk | Net sales
Net sales and long-lived asset information by geographic area
Concentration Risk, Percentage									6.00%	6.00%	6.00%
United States
Net sales and long-lived asset information by geographic area
Net sales									$ 836,768	$ 726,336	$ 642,164
Plant, Property & Equipment	300,820				265,004				300,820	265,004	182,434
Europe
Net sales and long-lived asset information by geographic area
Net sales									1,638,469	1,627,478	1,426,173
Plant, Property & Equipment	619,268				577,144				619,268	577,144	547,795
France
Net sales and long-lived asset information by geographic area
Net sales									895,110	862,364	744,856
Plant, Property & Equipment	338,288				308,250				338,288	308,250	266,804
Germany
Net sales and long-lived asset information by geographic area
Net sales									452,409	474,369	416,802
Plant, Property & Equipment	163,782				154,505				163,782	154,505	163,948
Italy
Net sales and long-lived asset information by geographic area
Net sales									141,867	144,044	131,523
Plant, Property & Equipment	53,562				54,978				53,562	54,978	57,080
Other Europe
Net sales and long-lived asset information by geographic area
Net sales									149,083	146,701	132,992
Plant, Property & Equipment	63,636				59,411				63,636	59,411	59,963
Other Foreign Countries
Net sales and long-lived asset information by geographic area
Net sales									384,495	410,947	400,946
Plant, Property & Equipment	$ 167,590				$ 149,465				$ 167,590	$ 149,465	$ 137,677