Our Assets and Liabilities with Recurring Fair Value Measurements (Details 1) (USD $) In Millions	Jun. 30, 2011		Dec. 31, 2010
Assets and liabilities accounted for at fair value [Line Items]
Cash equivalents	$ 1,334		$ 1,297	[1]
Margin deposits	133	[2]	162	[2]
Commodity futures contracts assets	460		550
Commodity forward contracts assets	218		341	[3]
Interest rate swaps assets	1		4
Total assets	2,146		2,354
Total liabilities	864		1,094
Margin deposits held by us posted by our counterparties		[2],[4]	6	[2],[4]
Commodity futures contracts liabilities	414		574
Commodity forward contracts liabilities	136		143	[3]
Interest rate swaps liabilities	314		371
Level 1
Assets and liabilities accounted for at fair value [Line Items]
Cash equivalents	1,334		1,297	[1]
Margin deposits	133		162
Commodity futures contracts assets	460		550
Commodity forward contracts assets				[3]
Interest rate swaps assets
Total assets	1,927		2,009
Total liabilities	414		580
Commodity futures contracts liabilities	414		574
Commodity forward contracts liabilities				[3]
Interest rate swaps liabilities
Level 2
Assets and liabilities accounted for at fair value [Line Items]
Cash equivalents				[1]
Margin deposits
Commodity futures contracts assets
Commodity forward contracts assets	173		287	[3]
Interest rate swaps assets	1		4
Total assets	174		291
Total liabilities	426		490
Commodity futures contracts liabilities
Commodity forward contracts liabilities	112		119	[3]
Interest rate swaps liabilities	314		371
Level 3
Assets and liabilities accounted for at fair value [Line Items]
Cash equivalents				[1]
Margin deposits
Commodity futures contracts assets
Commodity forward contracts assets	45		54	[3]
Interest rate swaps assets
Total assets	45		54
Total liabilities	24		24
Commodity futures contracts liabilities
Commodity forward contracts liabilities	24		24	[3]
Interest rate swaps liabilities

[1] At June 30, 2011, and December 31, 2010, we had cash equivalents of $1,144 million and $1,094 million included in cash and cash equivalents and $190 million and $203 million included in restricted cash, respectively.

[2] Balances are subject to master netting arrangements and presented on a gross basis on our Consolidated Condensed Balance Sheets. We do not offset fair value amounts recognized for derivative instruments executed with the same counterparty under a master netting arrangement for financial statement presentation.

[3] Includes OTC swaps and options.

[4] Included in other current liabilities on our Consolidated Condensed Balance Sheets.