Quarterly report pursuant to Section 13 or 15(d)

GOODWILL AND OTHER INTANGIBLE ASSETS AND LIABILITIES (Schedule Of Finite-Lived Intangible Assets By Major Class) (Details)

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GOODWILL AND OTHER INTANGIBLE ASSETS AND LIABILITIES (Schedule Of Finite-Lived Intangible Assets By Major Class) (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2013
Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]    
Definite lived intangible assets - Gross Carrying Amount $ 196.6 $ 196.5
Definite lived intangible assets - Accumulated Amortization (72.1) (67.5)
Definite lived intangible assets - Net Carrying Amount 124.5 129.0
Permits [Member] | Intangible Assets, Net [Member]
    
Finite-Lived Intangible Assets [Line Items]    
Definite lived intangible assets - Gross Carrying Amount 136.2 136.1
Definite lived intangible assets - Accumulated Amortization (33.5) (31.7)
Definite lived intangible assets - Net Carrying Amount 102.7 104.4
Utility Contracts [Member] | Intangible Assets, Net [Member]
    
Finite-Lived Intangible Assets [Line Items]    
Definite lived intangible assets - Gross Carrying Amount 54.7 54.7
Definite lived intangible assets - Accumulated Amortization (35.2) (32.4)
Definite lived intangible assets - Net Carrying Amount 19.5 22.3
Leases [Member] | Intangible Assets, Net [Member]
    
Finite-Lived Intangible Assets [Line Items]    
Definite lived intangible assets - Gross Carrying Amount 5.7 5.7
Definite lived intangible assets - Accumulated Amortization (3.4) (3.4)
Definite lived intangible assets - Net Carrying Amount 2.3 2.3
Below Market Sales Contracts [Member]
    
Finite-Lived Intangible Assets [Line Items]    
Definite lived intangible assets - Gross Carrying Amount (296.7) (296.7)
Definite lived intangible assets - Accumulated Amortization 183.5 181.6
Definite lived intangible assets - Net Carrying Amount (113.2) (115.1)
Below Market Sales Contracts [Member] | Other Current Liabilities [Member]
    
Finite-Lived Intangible Assets [Line Items]    
Definite lived intangible assets - Gross Carrying Amount (46.0) (46.0)
Definite lived intangible assets - Accumulated Amortization 1.9   
Definite lived intangible assets - Net Carrying Amount (44.1) (46.0)
Below Market Sales Contracts [Member] | Other Liabilities [Member]
    
Finite-Lived Intangible Assets [Line Items]    
Definite lived intangible assets - Gross Carrying Amount (250.7) (250.7)
Definite lived intangible assets - Accumulated Amortization 181.6 181.6
Definite lived intangible assets - Net Carrying Amount $ (69.1) $ (69.1)