Derivatives and Risk Management Activities (Details 4) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Impact of derivative activities recognized in earnings
Total	$ 136	$ (130)	$ 153	$ (196)
Commodity | Supply and Logistics segment revenues
Impact of derivative activities recognized in earnings
Total	103	(125)	100	(196)
Commodity | Facilities segment revenues
Impact of derivative activities recognized in earnings
Total	1	(5)	13	(6)
Commodity | Purchases and related costs
Impact of derivative activities recognized in earnings
Total	36	(1)	41	(1)
Commodity | Field Operating costs
Impact of derivative activities recognized in earnings
Total	(4)		(2)	1
Interest Rate Contracts | Interest expense
Impact of derivative activities recognized in earnings
Total			(1)	1
Net gain associated with interest rate swaps designated as fair value hedges	1		2	1
Foreign exchange contracts | Supply and Logistics segment revenues
Impact of derivative activities recognized in earnings
Total	(1)			3
Foreign exchange contracts | Other income/(expense), net
Impact of derivative activities recognized in earnings
Total	1	1	2	2
Derivatives designated as hedging instruments
Impact of derivative activities recognized in earnings
Total	(57)	(166)	(6)	(240)
Derivatives in Cash Flow Hedging Relationships - Ineffective Portion	1		(2)	(8)
Derivatives designated as hedging instruments | Commodity | Supply and Logistics segment revenues
Impact of derivative activities recognized in earnings
Total	(96)	(161)	(61)	(236)
Derivatives designated as hedging instruments | Commodity | Facilities segment revenues
Impact of derivative activities recognized in earnings
Total	1	(6)	13	(7)
Derivatives designated as hedging instruments | Commodity | Purchases and related costs
Impact of derivative activities recognized in earnings
Total	37		41
Derivatives designated as hedging instruments | Interest Rate Contracts | Interest expense
Impact of derivative activities recognized in earnings
Total			(1)	1
Derivatives designated as hedging instruments | Foreign exchange contracts | Other income/(expense), net
Impact of derivative activities recognized in earnings
Total	1	1	2	2
Derivatives not designated as hedging instruments
Impact of derivative activities recognized in earnings
Total	193	36	159	44
Derivatives not designated as hedging instruments | Commodity | Supply and Logistics segment revenues
Impact of derivative activities recognized in earnings
Total	199	36	161	40
Derivatives not designated as hedging instruments | Commodity | Facilities segment revenues
Impact of derivative activities recognized in earnings
Total		1		1
Derivatives not designated as hedging instruments | Commodity | Purchases and related costs
Impact of derivative activities recognized in earnings
Total	(1)	(1)		(1)
Derivatives not designated as hedging instruments | Commodity | Field Operating costs
Impact of derivative activities recognized in earnings
Total	(4)		(2)	1
Derivatives not designated as hedging instruments | Foreign exchange contracts | Supply and Logistics segment revenues
Impact of derivative activities recognized in earnings
Total	$ (1)			$ 3