Defined Benefit Plans - Defined Benefit Plans Narrative (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements and Curtailments	$ 1.5
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Contributions by Employer	1.0	5.5
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year	$ 5.8	$ 5.8