Price Risk Management Activities (Details) lb in Thousands, bu in Thousands, MMBTU in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($) MMBTU lb MBbls bu	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) MMBTU lb MBbls bu	Jun. 30, 2014 USD ($)
Price Risk Management Activities (Textual)
Compliance program costs | $	$ 55	$ 91	$ 188	$ 183
Foreign Currency Contracts [Member]
Price Risk Management Activities (Textual)
Monetary notional amount of derivative liabilities | $	$ 574		$ 574
Foreign currency commitments maturity date			Jul. 31, 2015
Fair Value Hedging [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	0		0
Cash Flow Hedging [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	0		0
Economic Hedging [Member] | Swap, Maturity Current Year [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	12,933		12,933
Economic Hedging [Member] | Swap, Maturity Current Year [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	12,355		12,355
Economic Hedging [Member] | Swap, Maturity Year Two [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	400		400
Economic Hedging [Member] | Swap, Maturity Year Two [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	300		300
Economic Hedging [Member] | Future, Maturity Current Year [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	50,688		50,688
Economic Hedging [Member] | Future, Maturity Current Year [Member] | Long (Purchases) [Member] | Grain (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives | bu	27,520		27,520
Economic Hedging [Member] | Future, Maturity Current Year [Member] | Long (Purchases) [Member] | Soybean Oil (in pounds) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives | lb	174,000		174,000
Economic Hedging [Member] | Future, Maturity Current Year [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	61,555		61,555
Economic Hedging [Member] | Future, Maturity Current Year [Member] | Short (Sales) [Member] | Grain (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives | bu	54,560		54,560
Economic Hedging [Member] | Future, Maturity Current Year [Member] | Short (Sales) [Member] | Soybean Oil (in pounds) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives | lb	268,980		268,980
Economic Hedging [Member] | Future, Maturity Year Two [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	448		448
Economic Hedging [Member] | Future, Maturity Year Two [Member] | Long (Purchases) [Member] | Grain (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives | bu	85		85
Economic Hedging [Member] | Future, Maturity Year Two [Member] | Long (Purchases) [Member] | Soybean Oil (in pounds) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives | lb	0		0
Economic Hedging [Member] | Future, Maturity Year Two [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	400		400
Economic Hedging [Member] | Future, Maturity Year Two [Member] | Short (Sales) [Member] | Grain (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives | bu	2,915		2,915
Economic Hedging [Member] | Future, Maturity Year Two [Member] | Short (Sales) [Member] | Soybean Oil (in pounds) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives | lb	0		0
Economic Hedging [Member] | Forward Contracts, Maturity Current Year [Member] | Long (Purchases) [Member] | Grain (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives | bu	28,091		28,091
Economic Hedging [Member] | Forward Contracts, Maturity Year Two [Member] | Long (Purchases) [Member] | Grain (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives | bu	3,142		3,142
Trading Derivatives [Member] | Swap, Maturity Current Year [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	3,521		3,521
Trading Derivatives [Member] | Swap, Maturity Current Year [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	3,521		3,521
Trading Derivatives [Member] | Swap, Maturity Year Two [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	180		180
Trading Derivatives [Member] | Swap, Maturity Year Two [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	180		180
Trading Derivatives [Member] | Future, Maturity Current Year [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	27,485		27,485
Trading Derivatives [Member] | Future, Maturity Current Year [Member] | Long (Purchases) [Member] | Natural Gas (in millions of BTUs) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives | MMBTU	2,150		2,150
Trading Derivatives [Member] | Future, Maturity Current Year [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	29,540		29,540
Trading Derivatives [Member] | Future, Maturity Current Year [Member] | Short (Sales) [Member] | Natural Gas (in millions of BTUs) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives | MMBTU	0		0
Trading Derivatives [Member] | Future, Maturity Year Two [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	500		500
Trading Derivatives [Member] | Future, Maturity Year Two [Member] | Long (Purchases) [Member] | Natural Gas (in millions of BTUs) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives | MMBTU	0		0
Trading Derivatives [Member] | Future, Maturity Year Two [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	0		0
Trading Derivatives [Member] | Future, Maturity Year Two [Member] | Short (Sales) [Member] | Natural Gas (in millions of BTUs) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives | MMBTU	0		0
Trading Derivatives [Member] | Options Held, Maturity Current Year [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	3,600		3,600
Trading Derivatives [Member] | Options Held, Maturity Current Year [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	3,912		3,912
Trading Derivatives [Member] | Options Held, Maturity Year Two [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	0		0
Trading Derivatives [Member] | Options Held, Maturity Year Two [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives	0		0