Postretirement Benefits Other Than Pensions - Components Of Comprehensive OPEB (Income) Expense (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Unrecognized Postretirement Benefit Costs Arising During the Year	$ 61.6	$ (29.4)	$ (53.9)
Amortization of Unrecognized Postretirement Benefit Costs	(25.0)	(16.2)	(8.7)
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost Earned During the Year	0.2	0.2	0.1
Interest Cost on Accumulated Benefit Obligation	1.2	1.6	1.9
Net Amortization and Deferral	(1.2)	(1.2)	(0.6)
Pension Expense Recognized	0.2	0.6	1.4
Unrecognized Postretirement Benefit Costs Arising During the Year	6.2	5.5	(4.4)
Amortization of Unrecognized Postretirement Benefit Costs	1.2	1.2	0.6
Comprehensive OPEB Expense	$ (4.8)	$ (3.7)	$ 6.4