Fair Value Measurements - Unobservable Input Or Level 3 Table and Footnote (Details) (USD $) In Millions, unless otherwise specified		12 Months Ended									12 Months Ended
	Dec. 31, 2012 Interest rate contract	Dec. 31, 2013 Fair Value, Inputs, Level 3 [Member] Natural Gas, Oil and NGL sales	Dec. 31, 2012 Fair Value, Inputs, Level 3 [Member] Natural Gas, Oil and NGL sales	Dec. 31, 2013 Fair Value, Inputs, Level 3 [Member] Interest Expense	Dec. 31, 2012 Fair Value, Inputs, Level 3 [Member] Interest Expense	Dec. 30, 2013 Fair Value, Inputs, Level 3 [Member] Commodity contracts	Dec. 30, 2012 Fair Value, Inputs, Level 3 [Member] Commodity contracts	Dec. 31, 2013 Fair Value, Inputs, Level 3 [Member] Commodity contracts	Dec. 31, 2012 Fair Value, Inputs, Level 3 [Member] Commodity contracts	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member] Commodity contracts	Dec. 30, 2013 Fair Value, Inputs, Level 3 [Member] Interest rate contract	Dec. 30, 2012 Fair Value, Inputs, Level 3 [Member] Interest rate contract	Dec. 31, 2013 Fair Value, Inputs, Level 3 [Member] Interest rate contract	Dec. 31, 2012 Fair Value, Inputs, Level 3 [Member] Interest rate contract	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member] Interest rate contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning balance	$ 0							$ (478)	$ (1,016)	$ (1,654)			$ 0	$ 0	$ 0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings Or Change In Net Assets Unrealized		410	567	(1)	6	410	567				(1)	6
Sales						0	0				1	(6)
Settlements						128	71				0	0
Ending balance	0							(478)	(1,016)	(1,654)			0	0	0
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss) Included in Other Income		$ 382	$ 374	$ 0	$ 0