Assets and Liabilities with Recurring Fair Value Measurements Fair Value Hierarchy (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 717	[1]	$ 1,134	[1]
Margin deposits	235	[2]	261	[2]
Commodity futures contracts	717		434
Commodity forward contracts	105	[3]	107	[3]
Interest Rate Swap Assets, Fair Value Disclosure	7		9
Total assets	1,781		1,945
Margin deposits held by us posted by our counterparties	18	[2],[4]	5	[2],[4]
Commodity futures contracts	684		495
Commodity forward contracts	148	[3]	70	[3]
Interest rate swaps	126		129
Liabilities, Fair Value Disclosure	976		699
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	717	[1]	1,134	[1]
Margin deposits	235		261
Commodity futures contracts	717		434
Commodity forward contracts	0	[3]	0	[3]
Interest Rate Swap Assets, Fair Value Disclosure	0		0
Total assets	1,669		1,829
Margin deposits held by us posted by our counterparties	18		5
Commodity futures contracts	684		495
Commodity forward contracts	0	[3]	0	[3]
Interest rate swaps	0		0
Liabilities, Fair Value Disclosure	702		500
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	[1]	0	[1]
Margin deposits	0		0
Commodity futures contracts	0		0
Commodity forward contracts	69	[3]	75	[3]
Interest Rate Swap Assets, Fair Value Disclosure	7		9
Total assets	76		84
Margin deposits held by us posted by our counterparties	0		0
Commodity futures contracts	0		0
Commodity forward contracts	120	[3]	52	[3]
Interest rate swaps	126		129
Liabilities, Fair Value Disclosure	246		181
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	[1]	0	[1]
Margin deposits	0		0
Commodity futures contracts	0		0
Commodity forward contracts	36	[3]	32	[3]
Interest Rate Swap Assets, Fair Value Disclosure	0		0
Total assets	36		32
Margin deposits held by us posted by our counterparties	0		0
Commodity futures contracts	0		0
Commodity forward contracts	28	[3]	18	[3]
Interest rate swaps	0		0
Liabilities, Fair Value Disclosure	$ 28		$ 18

[1] As of March 31, 2014 and December 31, 2013, we had cash equivalents of $478 million and $889 million included in cash and cash equivalents and $239 million and $245 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, and we do not offset amounts recognized for the right to reclaim, or the obligation to return, cash collateral with corresponding derivative instrument fair values. See Note 6 for further discussion of our derivative instruments subject to master netting arrangements.

[3] Includes OTC swaps and options.

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