Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2016

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, 2016 for each of the fair value hierarchy levels:

	Fair Value Measurement at September 30, 2016 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, 2016
	(in millions)
Assets:
Commodity derivatives	$	—	$	180	$	—	$	180
Deferred compensation plan assets	81		—		—		81
Total assets	81		180		—		261
Liabilities:
Commodity derivatives	—		19		—		19
Interest rate derivatives	—		8		—		8
Total liabilities	—		27		—		27
Total recurring fair value measurements	$	81	$	153	$	—	$	234

Fair Value Measurements, Nonrecurring [Table Text Block]

The following table presents the fair value and fair value adjustments (in millions) for the Company's 2016 and 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
	Impairment Date	Fair Value		Fair Value Adjustment			Oil		Gas
West Panhandle	March 2016	$	33	$	(32	)	$	49.77	$	3.24
South Texas - Eagle Ford Shale	December 2015	$	483	$	(846	)	$	52.82	$	3.34
South Texas - Other	September 2015	$	88	$	(72	)	$	57.41	$	3.46
West Panhandle	March 2015	$	61	$	(138	)	$	65.02	$	3.83

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, 2016 and December 31, 2015 are as follows:

	September 30, 2016				December 31, 2015
	Carrying Value		Fair Value		Carrying Value		Fair Value
	(in millions)
Commercial paper, corporate bonds and time deposits	$	2,052	$	2,052	$	275	$	275
Current portion of long-term debt	$	485	$	496	$	448	$	462
Long-term debt	$	2,726	$	3,022	$	3,207	$	3,206

Cash, Cash Equivalents and Investments [Table Text Block]

The following table provides the components of the Company's cash and cash equivalents and investments as of September 30, 2016:

	September 30, 2016
Consolidated Balance Sheet Location	Cash		Commercial Paper		Corporate Bonds		Time Deposits		Total
	(in millions)
Cash and cash equivalents	$	891	$	—	$	—	$	—	$	891
Short-term investments	—		742		459		532		1,733
Long-term investments	—		—		319		—		319
	$	891	$	742	$	778	$	532	$	2,943