Income Taxes (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Current:
Federal	$ (5.7)	$ 20.8	$ (33.8)
State	7.0	5.5	(2.4)
Foreign	6.4	5.4	5.0
Total current	7.7	31.7	(31.2)
Deferred:
Federal	126.6	62.2	65.4
State	3.2	1.3	3.5
Foreign	(3.5)	(3.0)	(0.4)
Total deferred	126.3	60.5	68.5
Provision for income taxes	$ 134.0	$ 92.2	$ 37.3