Income Taxes (Valuation Allowance) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Beginning balance	$ 378.7	$ 352.6	$ 247.8
Other deductions	(1.5)	(1.5)	(4.9)
Write off against valuation allowance	0	0	(41.3)
Acquisition and purchase accounting	0	0	(38.9)
Accumulated other comprehensive income (loss)	(8.2)	(33.4)	41.7
Ending balance	333.8	378.7	352.6
Increase to valuation allowance [Member]
Valuation allowance change	17.0	106.9	166.0
Decrease to valuation allowance [Member]
Valuation allowance change	$ (52.2)	$ (45.9)	$ (17.8)