SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018
SUPPLEMENTAL CASH FLOW INFORMATION [Abstract]
Interest (exclusive of amount capitalized)		$ 66,414	$ 62,021
Income taxes		34,297	(102,711)
Accrued liabilities for purchases of property, plant & equipment		30,259	21,257
Recognition of new asset retirement obligations		263	0
Right-of-use assets obtained in exchange for new operating lease liabilities		435,678	0
Amounts referable to business acquisitions Liabilities assumed	[1]	3,525	4,040
Amounts referable to business acquisitions Consideration payable to seller		$ 0	$ 4,500

[1] Includes adjustments to prior year acquisitions