ACQUISITIONS AND DIVESTITURES (Schedule Of Business Acquisitions) (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2018		Dec. 31, 2017
ACQUISITIONS AND DIVESTITURES [Abstract]
Cash			$ 1,072,978,000
Payable to seller			7,837,000
Total fair value of purchase consideration	$ 76,559,000		1,080,815,000
Accounts and notes receivable, net			14,955,000
Inventories			21,679,000
Other current assets			608,000
Investments			3,590,000
Property, plant & equipment			433,606,000
Contractual rights in place			295,482,000
Liabilities assumed			(3,894,000)
Net identifiable assets acquired			766,026,000
Goodwill	$ 7,840,000	[1]	27,497,000
Net Assets Divested Immediately Upon Acquisition			$ 287,292,000

[1] See Note 16 for a summary of acquisitions.