SUPPLEMENTAL CASH FLOW INFORMATION (Supplemental Information Referable to Condensed Consolidated Statements of Cash Flows) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SUPPLEMENTAL CASH FLOW INFORMATION [Abstract]
Interest (exclusive of amount capitalized)		$ 129,224	$ 128,217	$ 285,801
Income taxes		56,812	(65,968)	125,135
Accrued liabilities for purchases of property, plant & equipment		57,309	37,116	31,267
Recognition of new asset retirement obligations		263	20	1,920
Right-of-use assets obtained in exchange for new operating lease liabilities	[1]	444,547	0	0
Amounts referable to business acquisitions Liabilities assumed		4,373	5,405	3,876
Amounts referable to business acquisitions Consideration payable to seller		0	4,500	9,681
Fair value of noncash assets and liabilities exchanged		$ 0	$ 0	$ 9,900

[1] The 2019 amount includes the initial right-of-use assets resulting from our adoption of ASU 2016-02, “Leases,” as described in Note 1 under the captions Leases and New Accounting Standards.