Summary of Significant Accounting Policies Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Intangible Assets [Abstract]
Total Intangible Assets	$ 141.9	$ 141.9
Accumulated Amortization	14.5	4.9
Intangible Assets, Net (Excluding Goodwill)	127.4	137.0
Amortization of Intangible Assets	9.6	2.1	0.6
Amortization Expense, Next Twelve Months	9.5
Amortization Expense, Year Two	9.5
Amortization Expense, Year Three	9.5
Amortization Expense, Year Four	9.5
Amortization Expense, Year Five	$ 9.1