Pension and Postretirement Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Defined Benefit Plan Disclosure [Line Items]
Capitalized portion of defined benefit contribution percent	8.00%		8.00%
Amortization of:
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments	$ 0	$ 0	$ 0	$ 4.2
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year	26		26
Contributions to pension and postretirement plans			22.5
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service Cost	0.7	1.2	2.0	3.8
Interest cost on projected benefit obligation	5.3	6.2	16.0	18.6
Expected return on plan assets	(6.6)	(7.4)	(19.6)	(22.0)
Amortization of:
Prior Service Cost (benefit)	0	0.1	0.1	0.3
Defined Benefit Plan, Amortization of Gains (Losses)	4.8	3.6	14.5	10.7
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments			0	4.2
Benefit costs	4.2	3.7	13.0	15.6
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		22
Pension and Other Postretirement Benefit Contributions			16.0
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service Cost	0.2	0.1	0.4	0.3
Interest cost on projected benefit obligation	1.4	1.7	4.2	5.3
Expected return on plan assets	0	0	0	0
Amortization of:
Prior Service Cost (benefit)	(3.2)	(3.3)	(9.8)	(9.9)
Defined Benefit Plan, Amortization of Gains (Losses)	1.6	1.7	5.0	4.9
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments			0	0
Benefit costs	$ 0	$ 0.2	$ (0.2)	$ 0.6