Summary of Significant Accounting Policies Accumulated Other Comprehensive Income (Loss) Reclassifications out of AOCI (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Gains (Losses) on Cash Flow Hedges, Amount Reclassified from Accumulated OCI	$ 0
Amortization of Defined Benefit Pension Items, Amounts Reclassified from Accumulated OCI, Before Tax	(1.3)
Amortization of Defined Benefit Pension Items, Amount Reclassified from Accumulated OCI, Tax	(0.4)
Amortization of Defined Benefit Pension Items, Amount Reclassified from Accumulated OCI, Net of Tax	(0.9)
Amortization of Defined Benefit Pension Items, Amount Reclassified from Accumulated OCI, Noncontrolling Interest	(0.1)
Amortization of Defined Benefit Pension Items, Amount Reclassified from Accumulated OCI, Net of Tax and Noncontrolling Interest	(0.8)
Amortization of Defined Benefit Postretirement Items, Amount Reclassified from Accumulated OCI, Before Tax	0
Amounts Reclassified from Accumulated OCI, Net of Tax and Noncontrolling Interest	(0.8)
Commodity Contract [Member]
Gains (Losses) on Cash Flow Hedges, Amount Reclassified from Accumulated OCI	0.2
Interest Rate Swap [Member]
Gains (Losses) on Cash Flow Hedges, Amount Reclassified from Accumulated OCI	(0.2)
Actuarial Gains (Losses) [Member]
Amortization of Defined Benefit Pension Items, Amounts Reclassified from Accumulated OCI, Before Tax	(1.3)	[1]
Prior Service Cost [Member]
Amortization of Defined Benefit Postretirement Items, Amount Reclassified from Accumulated OCI, Before Tax	0.8	[1]
Actuarial Gains (Losses) [Member]
Amortization of Defined Benefit Postretirement Items, Amount Reclassified from Accumulated OCI, Before Tax	$ (0.8)	[1]

[1] These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost (see Note 12 for additional information).