Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2015

Fair Value Disclosures [Abstract]

Schedule of assets and liabilities measured at fair value on a recurring basis

The following table presents the Company's assets and liabilities that are measured at fair value on a recurring basis as of September 30, 2015 for each of the fair value hierarchy levels:

	Fair Value Measurement at September 30, 2015 Using
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value at September 30, 2015
	(in millions)
Assets:
Commodity derivatives	$	—	$	779	$	—	$	779
Deferred compensation plan assets	69		—		—		69
Total assets	69		779		—		848
Liabilities:
Commodity derivatives	—		1		—		1
Interest rate derivatives	—		2		—		2
Total liabilities	—		3		—		3
Total recurring fair value measurements	$	69	$	776	$	—	$	845

Fair Value Measurements, Nonrecurring [Table Text Block]

The following table presents the fair value and fair value adjustments (in millions) for the Company's March 2015 and September 2015 proved property impairments, as well as the average oil price per barrel ("Bbl") and gas price per British thermal unit ("MMBtu") utilized in respective Management's Price Outlooks:

							Management's Price Outlooks
		Fair Value		Fair Value Adjustment			Oil		Gas
West Panhandle	March 2015	$	61	$	(138	)	$	65.02	$	3.83
South Texas - Other	September 2015	$	88	$	(72	)	$	57.41	$	3.46

Fair Value of Assets Classified as Held for Sale [Table Text Block]

The following table presents the fair value adjustments made by the Company during 2014 related to assets associated with divestitures:

			Fair Value Adjustment
	Sales Value Less Costs to Sell		Three Months Ended September 30, 2014			Nine Months Ended September 30, 2014
	(in millions)
Hugoton field	$	328	$	(34	)	$	(34	)
Barnett Shale field	$	149	$	(46	)	$	(174	)
Pioneer Alaska	$	253	$	—		$	(97	)

Schedule of carrying values and financial instruments not carried at fair value

Carrying values and fair values of financial instruments that are not carried at fair value in the accompanying consolidated balance sheets as of September 30, 2015 and December 31, 2014 are as follows:

	September 30, 2015				December 31, 2014
	Carrying Value		Fair Value		Carrying Value		Fair Value
	(in millions)
Long-term debt	$	2,675	$	2,867	$	2,665	$	2,938