Derivative Instruments and Hedging Activities, Derivative Instruments and Hedging Activities, Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from OCI into Income - Effective Portion	$ (7.6)	$ 4.9
Revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from OCI into Income - Effective Portion	(6.3)	6.6
Interest Expense, Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from OCI into Income - Effective Portion	(1.3)	(1.7)
Commodity Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI - Effective Portion	(11.9)	(7.6)
Unrealized gain (loss) on hedges, before tax	(1.2)		(0.5)
Unrealized gain (loss) on hedges, after tax	(0.8)		(0.3)
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on hedges, before tax	(0.1)		(0.3)
Unrealized gain (loss) on hedges, after tax	$ (0.1)		$ (0.2)