GOODWILL AND OTHER INTANGIBLE ASSETS AND LIABILITIES (Schedule Of Finite-Lived Intangible Assets By Major Class) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Definite lived intangible assets - Gross Carrying Amount	$ 78.7	$ 78.4
Definite lived intangible assets - Accumulated Amortization	(25.1)	(24.6)
Definite lived intangible assets - Net Carrying Amount	53.6	53.8
Permits [Member] | Other Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Definite lived intangible assets - Gross Carrying Amount	78.7	78.4
Definite lived intangible assets - Accumulated Amortization	(25.1)	(24.6)
Definite lived intangible assets - Net Carrying Amount	$ 53.6	$ 53.8