Derivatives (Details) In Millions, unless otherwise specified	3 Months Ended		3 Months Ended
	Mar. 31, 2015 Derivatives designated as hedging instruments Fair value hedges Commodity contracts 2015 USD ($) bbl	Mar. 31, 2015 Derivatives not designated as hedging instruments USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Commodity contracts Long 2015 USD ($) bbl	Mar. 31, 2015 Derivatives not designated as hedging instruments Commodity contracts Long 2016 USD ($) bbl	Mar. 31, 2015 Derivatives not designated as hedging instruments Commodity contracts Long 2017 USD ($) bbl	Mar. 31, 2015 Derivatives not designated as hedging instruments Commodity contracts Short 2015 USD ($) bbl	Mar. 31, 2015 Derivatives not designated as hedging instruments Commodity contracts Short 2016 USD ($) bbl	Mar. 31, 2015 Derivatives not designated as hedging instruments Commodity contracts Short 2017 USD ($) bbl	Mar. 31, 2015 Derivatives not designated as hedging instruments Commodity contracts Short 2018 USD ($) bbl	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 AUD USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 AUD	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 AUD Weighted Average USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 CAD USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 CAD	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 CAD Weighted Average USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 DKK USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 DKK CLP	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 DKK Weighted Average USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 EUR USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 EUR EUR (€)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 EUR Weighted Average USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 GBP USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 GBP GBP (£)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 GBP Weighted Average USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 MXN USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 MXN	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 MXN Weighted Average USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 RON USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 RON	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 RON Weighted Average USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 ZAR USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 ZAR	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2015 ZAR Weighted Average USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2016 GBP USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2016 GBP GBP (£)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2016 GBP Weighted Average USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2017 GBP USD ($)	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2017 GBP NOK	Mar. 31, 2015 Derivatives not designated as hedging instruments Foreign currency contracts 2017 GBP Weighted Average USD ($)
Derivative instruments, at their respective fair value positions
Notional value of commodity contracts	4,400,000		44,100,000	6,800,000	200,000	34,900,000	4,300,000	200,000	100,000
Non-Designated, Notional amount of foreign currency contracts											0.5			27.9			15.7			€ 25.1			£ 59.7			123.8			35.3			53.8			£ 21.7			1.4
Weighted Average Fixed Price	56.203		54.721	49.795	39.786	70.043	69.663	42.019	83.997
Weighted Average Fixed Price												0.784			1.239			6.664			1.136			1.545			15.004			3.943			11.935			1.554			1.610
Weighted Average Mark-to-Market	1.500		(9.880)	(5.382)	(5.000)	13.169	5.512	6.000	3.000
Weighted Average Mark-to-Market										0.200			0.061			0.006			0.124			0.090			(0.002)			0.017			0.002			0.065			0.143
Fair Value Amount	$ 6.6	$ 24.0	$ (435.7)	$ (36.6)	$ (1.0)	$ 459.6	$ 23.7	$ 1.2	$ 0.3	$ 0.1			$ 1.7			$ 0.1			$ 3.1			$ 5.4			$ (0.2)			$ 0.6			$ 0.1			$ 1.4			$ 0.2