Accounting For Derivative Instruments And Hedging Activities (Derivative Activity For Instruments Classified As Qualifying Cash Flow Hedges) (Details) (USD $) In Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010
Derivatives, Fair Value [Line Items]
Fair Value Asset/(Liability)	$ 0		$ 0		$ 0		$ 0
Amount of Gain/(Loss) on Derivatives Recognized in OCI	(1.3)	[1]	0.7	[1]	0.6	[1]	(0.3)	[1]
Amount of Gain/(Loss) Reclassified From AOCI Into Income Effective Portion	0.5	[1]	(0.7)	[1]	1.5	[1]	(2.1)	[1]
Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Fair Value Asset/(Liability)	0		(0.3)		0		(0.3)
Amount of Gain/(Loss) on Derivatives Recognized in OCI	0	[1]	0	[1]	0	[1]	(0.1)	[1]
Amount of Gain/(Loss) Reclassified From AOCI Into Income Effective Portion	(0.2)	[1]	(0.4)	[1]	(0.5)	[1]	(1.2)	[1]
Diesel Fuel Derivatives [Member]
Derivatives, Fair Value [Line Items]
Fair Value Asset/(Liability)	0		0.3		0		0.3
Amount of Gain/(Loss) on Derivatives Recognized in OCI	(1.3)	[1]	0.7	[1]	0.6	[1]	(0.2)	[1]
Amount of Gain/(Loss) Reclassified From AOCI Into Income Effective Portion	$ 0.7	[1]	$ (0.3)	[1]	$ 2.0	[1]	$ (0.9)	[1]

[1] Changes in OCI and AOCI are reported in after-tax dollars.