Write-downs, Reserves, and Project Opening Costs, net of Recoveries (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Write-downs and reserves, net of recoveries:
Divestitures and abandonments	$ 59.1	$ 10.1	$ 29.0
Remediation costs	21.1	11.0	42.7
Write-down of long-term note receivable	0	0	52.2
Efficiency projects	17.5	46.6	1.4
Litigation reserves, awards, and settlements	(0.2)	3.2	20.9
Gain on Thistledown contribution	(11.0)	0	0
Other	7.1	(1.8)	1.4
Total write-downs and reserves, net of recoveries	93.6	69.1	147.6
Project opening costs	12.6	4.7	2.1
Total write-downs, reserves, and project opening costs, net of recoveries	$ 106.2	$ 73.8	$ 149.7