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Segment Reporting Income (Loss) From Continuing Operations (Details) $ in Millions, $ in Millions	3 Months Ended					9 Months Ended
	Sep. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Sep. 30, 2017 USD ($)	Mar. 31, 2017 CAD ($)	Mar. 31, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)
Segment Reporting
Income (loss) before income taxes	$ 410.1		$ 440.5			$ 1,290.5	$ 1,181.6
Other income (expense), net	0.2		(2.7)			0.2	0.2
Loss Contingency Accrual, Period Increase (Decrease)					$ (50.0)
Unrealized Gain (Loss) on Commodity Contracts	(23.2)		45.3			(62.8)	85.0
UNITED STATES
Segment Reporting
Income (loss) before income taxes	374.2		367.1			1,081.4	1,170.2
Canada [Member]
Segment Reporting
Income (loss) before income taxes	77.5		77.2			147.9	167.8
Europe [Member]
Segment Reporting
Income (loss) before income taxes	96.0		94.9			152.9	191.8
Europe [Member] \| Agrokor [Member]
Segment Reporting
Provision for Doubtful Accounts	4.0				11.0
International [Member]
Segment Reporting
Income (loss) before income taxes	(1.0)		(6.0)			4.0	(12.2)
Corporate [Member]
Segment Reporting
Income (loss) before income taxes	(136.6)		(92.7)			(95.7)	(336.0)
Purchase Price Adjustment [Member] \| Affiliated Entity [Member]
Segment Reporting
Other income (expense), net				$ 10.6	$ 8.1
Purchase Price Adjustment [Member]
Segment Reporting
AdjustmentAmount	$ 0.0	$ 328.0	$ 0.0			$ 328.0	$ 0.0