Pension Plans and Other Postretirement Benefits (Details7) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Comprehensive Income Amortization Of Defined Benefit Plan Net Prior Service Cost Credit Recognized In Net Periodic Benefit Cost Before Tax	$ 11.3	$ 13.4
Other Comprehensive Income Reclassification Of Defined Benefit Plans Net Gain Loss Recognized In Net Periodic Benefit Cost Before Tax	71.3	77.4
Remeasurements	(456.1)	(25.4)
Other Comprehensive Income Defined Benefit Plans Adjustment Before Tax Period Increase Decrease	(373.5)	65.4
Accumulated other comprehensive loss	(1,343.3)	(969.8)	(1,035.2)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Comprehensive Income Amortization Of Defined Benefit Plan Net Prior Service Cost Credit Recognized In Net Periodic Benefit Cost Before Tax	(18.3)	(18.1)
Other Comprehensive Income Reclassification Of Defined Benefit Plans Net Gain Loss Recognized In Net Periodic Benefit Cost Before Tax	9.9	6.0
Remeasurements	(60.2)	(11.3)
Other Comprehensive Income Defined Benefit Plans Adjustment Before Tax Period Increase Decrease	(68.6)	(23.4)
Accumulated other comprehensive loss	$ (158.6)	$ (90.0)	$ (66.6)