Pension and Postretirement Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Defined Benefit Plan Disclosure [Line Items]
Capitalized portion of defined benefit contribution percent	9.00%		9.00%
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments	$ 0	$ 0	$ 4.2	$ 0
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year	20.1		20.1
Defined Benefit Plan, Contributions by Employer			16.6
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Service Cost	1.2	1.3	3.8	3.9
Defined Benefit Plan, Interest Cost	6.2	6.7	18.6	20.1
Defined Benefit Plan, Expected Return on Plan Assets	(7.4)	(7.7)	(22.0)	(22.7)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0.1	0.2	0.3	0.4
Defined Benefit Plan, Amortization of Gains (Losses)	3.6	2.4	10.7	7.0
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments			4.2	0
Defined Benefit Plan, Net Periodic Benefit Cost	3.7	2.9	15.6	8.7
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year	22.1		22.1
Defined Benefit Plan, Contributions by Employer			18.3
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Service Cost	0.1	0	0.3	0.2
Defined Benefit Plan, Interest Cost	1.7	2.0	5.3	6.0
Defined Benefit Plan, Expected Return on Plan Assets	0	0	0	0
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(3.3)	(3.2)	(9.9)	(9.8)
Defined Benefit Plan, Amortization of Gains (Losses)	1.7	1.3	4.9	3.9
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments			0	0
Defined Benefit Plan, Net Periodic Benefit Cost	$ 0.2	$ 0.1	$ 0.6	$ 0.3