SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SUPPLEMENTAL CASH FLOW INFORMATION [Abstract]
Interest (exclusive of amount capitalized)		$ 128,217	$ 285,801	$ 135,039
Income taxes		(65,968)	125,135	102,849
Accrued liabilities for purchases of property, plant & equipment		37,116	31,267	26,676
Amounts referable to business acquisitions Liabilities assumed	[1]	5,405	3,876	798
Amounts referable to business acquisitions Consideration payable to seller		4,500	9,681	0
Fair value of noncash assets and liabilities exchanged		$ 0	$ 9,900	$ 0

[1] The 2018 amount includes adjustments to 2017 acquisitions.