Price Risk Management Activities (Details) (USD $) In Millions, unless otherwise specified							3 Months Ended		6 Months Ended		1 Months Ended																																																	3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2012 Refining Industry [Member]	Dec. 31, 2011 Refining Industry [Member]	Jun. 30, 2012 Financial Services Industry [Member]	Dec. 31, 2011 Financial Services Industry [Member]	Jun. 30, 2012 Interest Rate Swap [Member]	Jun. 30, 2011 Interest Rate Swap [Member]	Jun. 30, 2012 Interest Rate Swap [Member]	Jun. 30, 2011 Interest Rate Swap [Member]	Jul. 31, 2012 Forward Contracts [Member]	Jun. 30, 2012 Forward Contracts [Member]	Jun. 30, 2012 Fair Value Hedging [Member] Future [Member] Purchases (Long) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Fair Value Hedging [Member] Future [Member] Sales (Short) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Fair Value Hedging [Member] Forward Contracts [Member] Purchases (Long) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Cash Flow Hedging [Member] Swap [Member] Purchases (Long) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Cash Flow Hedging [Member] Swap [Member] Sales (Short) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Cash Flow Hedging [Member] Future [Member] Purchases (Long) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Cash Flow Hedging [Member] Future [Member] Sales (Short) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Cash Flow Hedging [Member] Forward Contracts [Member] Sales (Short) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Economic Hedging [Member] Swap [Member] Purchases (Long) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Economic Hedging [Member] Swap [Member] Purchases (Long) [Member] Maturity Year Two [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Economic Hedging [Member] Swap [Member] Sales (Short) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Economic Hedging [Member] Swap [Member] Sales (Short) [Member] Maturity Year Two [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Economic Hedging [Member] Future [Member] Purchases (Long) [Member] Maturity Current Year [Member] Emission Allowances [Member] Mg	Jun. 30, 2012 Economic Hedging [Member] Future [Member] Purchases (Long) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Economic Hedging [Member] Future [Member] Purchases (Long) [Member] Maturity Current Year [Member] Grain In Bushels [Member] Mbushel	Jun. 30, 2012 Economic Hedging [Member] Future [Member] Purchases (Long) [Member] Maturity Year Two [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Economic Hedging [Member] Future [Member] Purchases (Long) [Member] Maturity Year Two [Member] Grain In Bushels [Member] Mbushel	Jun. 30, 2012 Economic Hedging [Member] Future [Member] Sales (Short) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Economic Hedging [Member] Future [Member] Sales (Short) [Member] Maturity Current Year [Member] Grain In Bushels [Member] Mbushel	Jun. 30, 2012 Economic Hedging [Member] Future [Member] Sales (Short) [Member] Maturity Year Two [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Economic Hedging [Member] Future [Member] Sales (Short) [Member] Maturity Year Two [Member] Grain In Bushels [Member] Mbushel	Jun. 30, 2012 Economic Hedging [Member] Forward Contracts [Member] Purchases (Long) [Member] Maturity Current Year [Member] Grain In Bushels [Member] Mbushel	Jun. 30, 2012 Economic Hedging [Member] Forward Contracts [Member] Purchases (Long) [Member] Maturity Year Two [Member] Grain In Bushels [Member] Mbushel	Jun. 30, 2012 Trading Derivatives [Member] Swap [Member] Purchases (Long) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Trading Derivatives [Member] Swap [Member] Purchases (Long) [Member] Maturity Current Year [Member] Grain In Bushels [Member] Mbushel	Jun. 30, 2012 Trading Derivatives [Member] Swap [Member] Purchases (Long) [Member] Maturity Year Two [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Trading Derivatives [Member] Swap [Member] Purchases (Long) [Member] Maturity Year Two [Member] Grain In Bushels [Member] Mbushel	Jun. 30, 2012 Trading Derivatives [Member] Swap [Member] Sales (Short) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Trading Derivatives [Member] Swap [Member] Sales (Short) [Member] Maturity Current Year [Member] Grain In Bushels [Member] Mbushel	Jun. 30, 2012 Trading Derivatives [Member] Swap [Member] Sales (Short) [Member] Maturity Year Two [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Trading Derivatives [Member] Swap [Member] Sales (Short) [Member] Maturity Year Two [Member] Grain In Bushels [Member] Mbushel	Jun. 30, 2012 Trading Derivatives [Member] Future [Member] Purchases (Long) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Trading Derivatives [Member] Future [Member] Purchases (Long) [Member] Maturity Current Year [Member] Natural Gas In Btus [Member] BBTU	Jun. 30, 2012 Trading Derivatives [Member] Future [Member] Purchases (Long) [Member] Maturity Current Year [Member] Grain In Bushels [Member] Mbushel	Jun. 30, 2012 Trading Derivatives [Member] Future [Member] Purchases (Long) [Member] Maturity Year Two [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Trading Derivatives [Member] Future [Member] Purchases (Long) [Member] Maturity Year Two [Member] Natural Gas In Btus [Member] BBTU	Jun. 30, 2012 Trading Derivatives [Member] Future [Member] Purchases (Long) [Member] Maturity Year Two [Member] Grain In Bushels [Member] Mbushel	Jun. 30, 2012 Trading Derivatives [Member] Future [Member] Sales (Short) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Trading Derivatives [Member] Future [Member] Sales (Short) [Member] Maturity Current Year [Member] Natural Gas In Btus [Member] BBTU	Jun. 30, 2012 Trading Derivatives [Member] Future [Member] Sales (Short) [Member] Maturity Current Year [Member] Grain In Bushels [Member] Mbushel	Jun. 30, 2012 Trading Derivatives [Member] Future [Member] Sales (Short) [Member] Maturity Year Two [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Trading Derivatives [Member] Future [Member] Sales (Short) [Member] Maturity Year Two [Member] Natural Gas In Btus [Member] BBTU	Jun. 30, 2012 Trading Derivatives [Member] Future [Member] Sales (Short) [Member] Maturity Year Two [Member] Grain In Bushels [Member] Mbushel	Jun. 30, 2012 Trading Derivatives [Member] Options Held [Member] Purchases (Long) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Trading Derivatives [Member] Options Held [Member] Purchases (Long) [Member] Maturity Year Two [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Trading Derivatives [Member] Options Held [Member] Sales (Short) [Member] Maturity Current Year [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Trading Derivatives [Member] Options Held [Member] Sales (Short) [Member] Maturity Year Two [Member] Crude Oil In Barrels [Member] MBbls	Jun. 30, 2012 Biofuels Blending [Member]	Jun. 30, 2011 Biofuels Blending [Member]	Jun. 30, 2012 Biofuels Blending [Member]	Jun. 30, 2011 Biofuels Blending [Member]	Jun. 30, 2012 Minimum Inventory [Member]	Jun. 30, 2012 Minimum Inventory [Member]	Jun. 30, 2012 Emissions Allowance [Member]	Jun. 30, 2012 Emissions Allowance [Member]
Volume of outstanding contracts
Nonmonetary notional amount of price risk derivatives													4,869,000	9,052,000	4,183,000	5,511,000	5,511,000	18,386,000	10,768,000	7,618,000	30,879,000	0	28,174,000	0	55,000	58,610,000	49,750,000	85,000	55,000	79,986,000	91,035,000	0	3,375,000	38,336,000	3,610,000	19,043,000	2,605,000	27,930,000	0	17,917,000	12,460,000	28,321,000	1,580,000	101,095,000	6,800,000	19,360,000	18,832,000	200,000	0	102,208,000	6,400,000	19,360,000	17,760,000	0	0	11,900,000	0	12,271,000	0
Price Risk Management Activities (Textual)
Compliance program costs																																																												$ 59	$ 39	$ 126	$ 95	$ 1	$ 3	$ 0	$ 1
Notional amount of interest rate derivatives	0	0
Interest rate derivatives activity							0	0	0	0
Notional amount of foreign currency derivative purchase contracts												634
Foreign currency commitments maturity date											Jul. 31, 2012
Net receivables related to derivative instruments from counterparties			$ 7	$ 2	$ 0	$ 0