Employee Benefit Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Defined Benefit and Defined Contribution Plan Disclosure [Line Items]
Total pension plan costs	$ 41,000,000		$ 37,000,000		$ 36,000,000
Company contributions to foreign pension plans	5,000,000		4,000,000		3,000,000
Benefit obligation	14,000,000		13,000,000
Fair value of foreign pension plan assets	12,000,000		11,000,000
Accrued benefit cost	(1,000,000)		(1,000,000)
Stock based compensation by job function [Line Items]
Compensation expense related to the company's stock-based compensation plans	144,842,000		134,467,000		127,504,000
Federal income tax (expense) / benefit recognized from stock-based compensation	99,000,000		56,000,000		67,000,000
Maximum Percentage Of Employee Pay Eligible For Contribution To Espp Percentage	10.00%
Stock-based compensation expense related to stock options, SAR and ESPP grants	62,000,000		53,000,000		49,000,000
Percentage of fair market value at which employees may purchase company stock via the ESPP	85.00%
Performance Units and Performance Stock [Member]
Weighted Average Fair Value And Valuation Assumptions Used To Value Stock-Based Compensation [Abstract]
Weighted Average Fair Value of Grants	$ 119.27		$ 100.34		$ 67.05
Expected Volatility (in hundredths)	32.18%		33.63%		36.39%
Risk-Free Interest Rate (in hundredths)	1.18%		0.79%		0.39%
Share-Based Compensation Arrangement By Share-Based Payment Award [Abstract]
Weighted average period over which unrecognized compensation expense will be recognized	3 years 9 months 18 days
Unrecognized compensation expense	5,000,000
Number of Shares and Units [Roll Forward]
Outstanding at January 1 (in shares)	261,000	[1]	142,000	[1]	0
Granted (in shares)	72,000		119,000		142,000
Outstanding at December 31 (in shares)	333,000	[1]	261,000	[1]	142,000	[1]
Weighted Average Grant Fair Value [Abstract]
Outstanding at January 1 (in dollars per share)	$ 82.18	[1]	$ 67.05	[1]	$ 0
Granted (in dollars per share)	$ 119.27		$ 100.34		$ 67.05
Outstanding at December 31 (in dollars per share)	$ 90.17	[1]	$ 82.18	[1]	$ 67.05	[1]
Intrinsic value of stock based compensation	30,700,000		21,900,000
Maximum vest period from the date of grant	5 years
Performance Units and Performance Stock [Abstract]
Minimum Performance Units and Stock Allowed to be Outstanding	0
Maximum performance units and stock allowed to be outstanding	666,390
Share Based Compensation Arrangement By Performance Units and Stock Compensation Cost	9,000,000		9,000,000		7,000,000
Term of Zero-Coupon Risk-Free Interest Rate Derived from the Treasury Constant Maturities Yield Curve	3 years 3 months 4 days
Performance Period for Performance Units and Stock	3 years
ESPP [Member]
Weighted Average Fair Value And Valuation Assumptions Used To Value Stock-Based Compensation [Abstract]
Weighted Average Fair Value of Grants	$ 21.65		$ 15.06		$ 12.56
Expected Volatility (in hundredths)	25.03%		29.89%		40.92%
Risk-Free Interest Rate (in hundredths)	0.08%		0.11%		0.11%
Dividend Yield (in hundredths)	0.46%		0.60%		0.60%
Expected Life (in years)	6 months		6 months		6 months
Share-Based Compensation Arrangement By Share-Based Payment Award [Abstract]
Common Shares Available for Grant	794,000
Approximate Number of Participants	1,991		1,844		1,705
Shares Purchased	202,000		256,000		328,000
Aggregate Purchase Price	14,927,000		14,015,000		12,522,000
Stock Options and SARS [Member]
Stock based compensation by job function [Line Items]
Maximum term of stock options and SARs granted	10 years
Weighted Average Fair Value And Valuation Assumptions Used To Value Stock-Based Compensation [Abstract]
Weighted Average Fair Value of Grants	$ 30.75		$ 27.35		$ 18.98
Expected Volatility (in hundredths)	35.28%		35.86%		39.68%
Risk-Free Interest Rate (in hundredths)	0.95%		0.78%		0.45%
Dividend Yield (in hundredths)	0.61%		0.40%		0.60%
Expected Life (in years)	5 years 2 months 12 days		5 years 6 months		5 years 7 months 6 days
Stock option and SAR Rollforward [Abstract]
Outstanding at January 1 (in shares)	10,452,000		12,438,000		16,748,000
Granted (in shares)	2,146,000		2,268,000		2,480,000
Exercised (in shares)	(1,718,000)	[2]	(4,046,000)	[2]	(6,492,000)	[2]
Forfeited (in shares)	(387,000)		(208,000)		(298,000)
Outstanding at December 31 (in shares)	10,493,000		10,452,000		12,438,000
Share-Based Compensation Arrangement By Share-Based Payment Award [Abstract]
Outstanding at January 1 (in dollars per share)	$ 54.43		$ 42.91		$ 35.01
Granted (in dollars per share)	$ 101.55		$ 83.70		$ 55.99
Exercised (in dollars per share)	$ 45.68	[2]	$ 35.62	[2]	$ 27.40	[2]
Forfeited (in dollars per share)	$ 68.95		$ 50.78		$ 45.59
Outstanding at December 31 (in dollars per share)	$ 64.96		$ 54.43		$ 42.91
Stock Options/SARs Exercisable at December 31 (in shares)	5,287,000		4,638,000		6,286,000
Stock Options/SARs Exercisable at December 31 (in dollars per share)	$ 49.40		$ 43.95		$ 37.49
Intrinsic value of stock options/SARs exercised during the period	95,000,000	[2]	151,000,000	[2]	185,000,000	[2]
Stock options/SARs vested or expected to vest (in shares)	10,100,000
Weighted average grant price for stock options/SARs vested or expected to vest (per share)	$ 64.29
Intrinsic value of stock options/SARs vested or expected to vest	299,000,000
Weighted Average Remaining Contractual Life for Stock Options/SARs Vested or Expected to Vest	4 years 3 months 18 days
Common Shares Available for Grant	28,700,000
Weighted average period over which unrecognized compensation expense will be recognized	2 years 8 months 12 days
Unrecognized compensation expense	112,000,000
Weighted Average Grant Fair Value [Abstract]
Maximum vest period from the date of grant	4 years
Summary Information By Grant Price Range For Stock Options And SARs Outstanding And Exercisable At End Of Period [Line Items]
Stock Options and SARs Outstanding	10,493,000
Weighted Average Remaining Life for Outstanding Options and SARs	4 years
Weighted Average Grant Price For Outstanding Options and SARs	$ 64.96
Aggregate Intrinsic Value For Outstanding Options and SARs	304,679.00	[3]
Stock Options and SARs Exercisable	5,287,000
Weighted Average Remaining Life For Exercisable Units	3 years
Weighted Average Grant Price For Exercisable Options and SARs	$ 49.40
Aggregate Intrinsic Value For Exercisable Units	225,692.00	[3]
Stock Options and SARS [Member] | $22.00 to $ 42.99
Summary Information By Grant Price Range For Stock Options And SARs Outstanding And Exercisable At End Of Period [Line Items]
Stock Options and SARs Outstanding	2,682,000
Weighted Average Remaining Life for Outstanding Options and SARs	3 years
Weighted Average Grant Price For Outstanding Options and SARs	$ 40.74
Stock Options and SARs Exercisable	2,129,000
Weighted Average Remaining Life For Exercisable Units	3 years
Weighted Average Grant Price For Exercisable Options and SARs	$ 40.50
Stock Options and SARS [Member] | 43.00 to 46.99
Summary Information By Grant Price Range For Stock Options And SARs Outstanding And Exercisable At End Of Period [Line Items]
Stock Options and SARs Outstanding	1,612,000
Weighted Average Remaining Life for Outstanding Options and SARs	2 years
Weighted Average Grant Price For Outstanding Options and SARs	$ 45.57
Stock Options and SARs Exercisable	1,598,000
Weighted Average Remaining Life For Exercisable Units	2 years
Weighted Average Grant Price For Exercisable Options and SARs	$ 45.58
Stock Options and SARS [Member] | 47.00 to 56.99
Summary Information By Grant Price Range For Stock Options And SARs Outstanding And Exercisable At End Of Period [Line Items]
Stock Options and SARs Outstanding	2,014,000
Weighted Average Remaining Life for Outstanding Options and SARs	4 years
Weighted Average Grant Price For Outstanding Options and SARs	$ 55.80
Stock Options and SARs Exercisable	995,000
Weighted Average Remaining Life For Exercisable Units	4 years
Weighted Average Grant Price For Exercisable Options and SARs	$ 55.57
Stock Options and SARS [Member] | 57.00 to 84.99
Summary Information By Grant Price Range For Stock Options And SARs Outstanding And Exercisable At End Of Period [Line Items]
Stock Options and SARs Outstanding	2,099,000
Weighted Average Remaining Life for Outstanding Options and SARs	5 years
Weighted Average Grant Price For Outstanding Options and SARs	$ 83.08
Stock Options and SARs Exercisable	548,000
Weighted Average Remaining Life For Exercisable Units	5 years
Weighted Average Grant Price For Exercisable Options and SARs	$ 82.44
Stock Options and SARS [Member] | 85.00 to 116.99
Summary Information By Grant Price Range For Stock Options And SARs Outstanding And Exercisable At End Of Period [Line Items]
Stock Options and SARs Outstanding	2,086,000
Weighted Average Remaining Life for Outstanding Options and SARs	7 years
Weighted Average Grant Price For Outstanding Options and SARs	$ 101.70
Stock Options and SARs Exercisable	17,000
Weighted Average Remaining Life For Exercisable Units	3 years
Weighted Average Grant Price For Exercisable Options and SARs	$ 97.77
Restricted Stock And Restricted Stock Units [Member]
Stock option and SAR Rollforward [Abstract]
Outstanding at January 1 (in shares)	7,358,000	[4]	7,636,000	[4]	8,480,000
Granted (in shares)	1,132,000		1,294,000		1,534,000
Exercised (in shares)	(2,761,000)	[5]	(1,368,000)	[5]	(2,118,000)	[5]
Forfeited (in shares)	(335,000)		(204,000)		(260,000)
Outstanding at December 31 (in shares)	5,394,000	[4]	7,358,000	[4]	7,636,000	[4]
Share-Based Compensation Arrangement By Share-Based Payment Award [Abstract]
Outstanding at January 1 (in dollars per share)	$ 49.54	[4]	$ 45.53		$ 41.47
Granted (in dollars per share)	$ 98.72		$ 76.04		$ 56.09
Exercised (in dollars per share)	$ 105.24	[5]	$ 52.39	[5]	$ 36.35	[5]
Forfeited (in dollars per share)	$ 62.55		$ 48.55		$ 42.68
Outstanding at December 31 (in dollars per share)	$ 64.39	[4]	$ 49.54	[4]	$ 45.53
Weighted average period over which unrecognized compensation expense will be recognized	2 years 6 months
Unrecognized compensation expense	178,000,000
Share Based Compensation Arrangement By Restricted Stock And Restricted Stock Units Compensation Cost	74,000,000		72,000,000		72,000,000
Weighted Average Grant Fair Value [Abstract]
Intrinsic value of stock based compensation	291,000,000		101,000,000		120,000,000
Intrinsic Value Of Restricted Stock And Restricted Stock Units Outstanding	497,000,000		617,000,000
Maximum vest period from the date of grant	5 years
Lease And Well [Member]
Stock based compensation by job function [Line Items]
Compensation expense related to the company's stock-based compensation plans	41,000,000		35,000,000		35,000,000
Gathering And Processing Costs [Member]
Stock based compensation by job function [Line Items]
Compensation expense related to the company's stock-based compensation plans	1,000,000		1,000,000		1,000,000
Exploration Costs [Member]
Stock based compensation by job function [Line Items]
Compensation expense related to the company's stock-based compensation plans	27,000,000		27,000,000		27,000,000
General And Administrative [Member]
Stock based compensation by job function [Line Items]
Compensation expense related to the company's stock-based compensation plans	$ 76,000,000		$ 71,000,000		$ 65,000,000

[1] The total intrinsic value of performance units and performance stock outstanding at December 31, 2014 and 2013 was $30.7 million and $21.9 million, respectively.

[2] The total intrinsic value of stock options/SARs exercised during the years 2014, 2013 and 2012 was $95 million, $151 million and $185 million, respectively. The intrinsic value is based upon the difference between the market price of the Common Stock on the date of exercise and the grant price of the stock options/SARs.

[3] Based upon the difference between the closing market price of the Common Stock on the last trading day of the year and the grant price of in-the-money stock options and SARs.

[4] The total intrinsic value of restricted stock and restricted stock units outstanding at December 31, 2014 and 2013 was approximately $497 million and $617 million, respectively.

[5] The total intrinsic value of restricted stock and restricted stock units released during the years ended December 31, 2014, 2013 and 2012 was $291 million, $101 million and $120 million, respectively. The intrinsic value is based upon the closing price of EOG's common stock on the date restricted stock and restricted stock units are released.