SEGMENT INFORMATION (Geographic Split of Net Sales and Property, Plant and Equipment ) (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
Geographic split of the Company's net sales, based on the location of the customer, and property, plant and equipment
Net Sales	$ 736,307	$ 730,783	$ 777,008	$ 759,174	$ 743,827	$ 737,099	$ 790,052	$ 757,696	$ 3,003,272	$ 3,028,674	$ 2,624,431
Total property, plant and equipment, net	$ 529,344				$ 478,801				$ 529,344	$ 478,801	$ 477,031
Percentage of LIFO Inventory	36.00%				37.00%				36.00%	37.00%	32.00%
United States
Geographic split of the Company's net sales, based on the location of the customer, and property, plant and equipment
Net Sales									$ 1,615,483	$ 1,554,688	$ 1,388,816
Total property, plant and equipment, net	$ 250,923				$ 214,943				250,923	214,943	194,491
Other foreign countries
Geographic split of the Company's net sales, based on the location of the customer, and property, plant and equipment
Net Sales									1,387,789	1,473,986	1,235,615
Total property, plant and equipment, net	278,566				264,110				278,566	264,110	282,931
Corporate / Eliminations
Geographic split of the Company's net sales, based on the location of the customer, and property, plant and equipment
Total property, plant and equipment, net	$ (145)				$ (252)				$ (145)	$ (252)	$ (391)
Customer Concentration Risk [Member] | Sales Revenue, Goods, Net [Member] | Maximum
Geographic split of the Company's net sales, based on the location of the customer, and property, plant and equipment
Concentration Risk, Percentage									10.00%	10.00%	10.00%