Pension Benefits and Postretirement Benefits Other Than Pensions (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost on Benefits Earned	$ 2.5	$ 2.0	$ 5.1	$ 4.5
Interest Cost on Projected Benefit Obiligation	5.8	5.7	11.5	11.2
Expected Return on Plan Assets	(6.1)	(5.9)	(12.2)	(11.8)
Net Amortization and Deferral	2.6	0.7	4.7	1.1
Net Periodic Benefit Cost	4.8	2.5	9.1	5.0
Postretirement Benefits Other than Pensions [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost on Benefits Earned	0.1	0.1	0.1	0.1
Interest Cost on Projected Benefit Obiligation	0.4	0.5	0.9	1.0
Net Amortization and Deferral	(0.1)	(0.1)	(0.3)	(0.5)
Net Periodic Benefit Cost	$ 0.4	$ 0.5	$ 0.7	$ 0.6