GOODWILL AND OTHER INTANGIBLE ASSETS AND LIABILITIES (Schedule Of Finite-Lived Intangible Assets By Major Class) (Details) - Permits [Member] - Other Assets [Member] - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Definite lived intangible assets - Gross Carrying Amount	$ 78.8	$ 78.4
Definite lived intangible assets - Accumulated Amortization	(26.5)	(24.6)
Definite lived intangible assets - Net Carrying Amount	$ 52.3	$ 53.8