Other Operating-Net (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		1 Months Ended	3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Feb. 28, 2011 GROWMARK, Inc. item	Sep. 30, 2012 Loss on disposal of property, plant and equipment and non-core assets - net	Sep. 30, 2011 Loss on disposal of property, plant and equipment and non-core assets - net	Sep. 30, 2012 Loss on disposal of property, plant and equipment and non-core assets - net	Sep. 30, 2011 Loss on disposal of property, plant and equipment and non-core assets - net	Sep. 30, 2012 Engineering studies	Sep. 30, 2012 Engineering studies	Sep. 30, 2012 Bartow costs	Sep. 30, 2011 Bartow costs	Sep. 30, 2012 Bartow costs	Sep. 30, 2011 Bartow costs	Sep. 30, 2012 Other	Sep. 30, 2011 Other	Sep. 30, 2012 Other	Sep. 30, 2011 Other
Other operating-Net
Other operating - net	$ 8.6	$ 39.4	$ 41.7	$ 12.3		$ 0.4	$ 37.0	$ 4.0	$ 6.1	$ 2.9	$ 14.7	$ 0.8	$ 1.4	$ 2.4	$ 3.2	$ 4.5	$ 1.0	$ 20.6	$ 3.0
Non-cash impairment charge		35.1
Number of dry product warehouses sold					4
Pre-tax gain (loss) on sale of assets			$ (4.0)	$ (7.4)	$ 32.5