Stock-Based Compensation (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Stock based compensation by job function [Line Items]
Compensation expense related to the company's stock-based compensation plans	$ 45.5		$ 45.9		$ 103.2		$ 101.3
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized					15,500,000
Common Shares Available for Grant	16,600,000				16,600,000
Stock Options/SARs and Employee Stock Purchase Plan (ESPP) Disclosures [Line Items]
Stock-based compensation expense related to stock options, SAR and ESPP grants	19.2		16.5		40.0		37.8
Performance Units and Performance Stock [Abstract]
Term Of Zero- Coupon Risk- Free Interest Rate In Years Derived From Treasury Constant Maturities Yield Curve	3.26				3.26
Stock Options and SARs [Member]
Weighted Average Fair Values And Valuation Assumptions Used To Value Stock Option/SARs, ESPP, and Performance Units/Stock Stock-Based Compensation [Abstract]
Weighted Average Fair Value of Grants					$ 54.68		$ 37.94
Expected Volatility (in hundredths)					35.86%		39.68%
Risk-Free Interest Rate (in hundredths)					0.78%		0.45%
Dividend Yield (in hundredths)					0.40%		0.60%
Expected Life (in years)					5 years 6 months		5 years 7 months 6 days
Stock Options and SARs Rollforward [Abstract]
Outstanding at January 1 (in shares)					6,219,000		8,374,000
Granted (in shares)					1,117,000		1,223,000
Exercised (1) (in shares)					(1,824,000)	[1]	(2,044,000)	[1]
Forfeited (in shares)					(84,000)		(124,000)
Outstanding at September 30 (in shares)	5,428,000	[2]	7,429,000	[2]	5,428,000	[2]	7,429,000	[2]
Share-Based Compensation Arrangement By Share Based Payment Award Stock Option/SARs, ESPP, Restricted Stock/Units and Performance Units/Stock [Abstract]
Outstanding at January 1 (price per share)					$ 85.81		$ 70.01
Granted (price per share)					$ 167.32		$ 111.91
Exercised (1) (price per share)					$ 69.03	[1]	$ 53.52	[1]
Forfeited (price per share)					$ 96.76		$ 89.95
Outstanding at September 30 (price per share)	$ 108.06	[2]	$ 81.11	[2]	$ 108.06	[2]	$ 81.11	[2]
Stock Options and SARs Vested or Expected to Vest (in shares)	5,199,000	[3]	7,184,000	[3]	5,199,000	[3]	7,184,000	[3]
Weighted average grant price for stock options/SARs vested or expected to vest (price per share)	$ 107.26	[3]	$ 80.57	[3]	$ 107.26	[3]	$ 80.57	[3]
Stock Options and SARs Exercisable at September 30 (in shares)	2,491,000	[4]	4,315,000	[4]	2,491,000	[4]	4,315,000	[4]
Stock Options and SARs Exercisable at September 30 (price per share)	$ 88.05	[4]	$ 69.87	[4]	$ 88.05	[4]	$ 69.87	[4]
Intrinsic value of stock options/SARs exercised during the period					134.2		110.8
Aggregate intrinsic value for outstanding stock options and SARs	332.3		231.1		332.3		231.1
Weighted average remaining contractual life for stock options/SARs outstanding (in years)					4 years 9 months 18 days		4 years 1 month 6 days
Aggregate intrinsic value of stock options/SARs vested or expected to vest	322.5		227.3		322.5		227.3
Weighted average remaining contractual life for stock options/SARs vested or expected to vest (in years)					4 years 8 months 12 days		4 years
Aggregate intrinsic value for exercisable units	202.4		182.7		202.4		182.7
Weighted average remaining contractual life for exercisable options/SARs (in years)					3 years 6 months		2 years 8 months 12 days
Unrecognized compensation expense	115.5				115.5
Weighted average period over which unrecognized compensation expense will be recognized (in years)					2 years 10 months 24 days
ESPP [Member]
Weighted Average Fair Values And Valuation Assumptions Used To Value Stock Option/SARs, ESPP, and Performance Units/Stock Stock-Based Compensation [Abstract]
Weighted Average Fair Value of Grants					$ 30.13		$ 25.17
Expected Volatility (in hundredths)					29.89%		41.04%
Risk-Free Interest Rate (in hundredths)					0.11%		0.11%
Dividend Yield (in hundredths)					0.60%		0.60%
Expected Life (in years)					6 months		6 months
Restricted Stock and Restricted Stock Units [Member]
Share-Based Compensation Arrangement By Share Based Payment Award Stock Option/SARs, ESPP, Restricted Stock/Units and Performance Units/Stock [Abstract]
Unrecognized compensation expense	171.8				171.8
Weighted average period over which unrecognized compensation expense will be recognized (in years)							2 years 8 months 12 days
Share-Based Compensation Arrangement By Restricted Stock And Restricted Stock Units Compensation Cost	19.2		23.1		55.5		57.2
Restricted Stock/Restricted Stock Units and Performance Units/Performance Stock [Roll Forward]
Outstanding at January 1 (in shares)					3,818,000		4,240,000
Granted (in shares)					642,000		757,000
Released (in shares)					(617,000)	[5]	(977,000)	[5]
Forfeited (in shares)					(80,000)		(106,000)
Outstanding at September 30 (in shares)	3,763,000	[6]	3,914,000	[6]	3,763,000	[6]	3,914,000	[6]
Weighted Average Grant Price Restricted Stock and Restricted Stock Units/Performance Units and Performance Stock [Roll Forward]
Outstanding at January 1 (price per share)					$ 91.06		$ 82.93
Granted (price per share)					$ 151.85		$ 112.13
Released (price per share)					$ 105.77	[5]	$ 72.97	[5]
Forfeited (price per share)					$ 95.39		$ 88.36
Outstanding at September 30 (price per share)	$ 98.93	[6]	$ 90.91	[6]	$ 98.93	[6]	$ 90.91	[6]
Intrinsic value of restricted stock and restricted stock units released during the year					89.2		110.7
Aggregate intrinsic value of stock and units outstanding	637.0		438.6		637.0		438.6
Performance Units and Performance Stock [Member]
Weighted Average Fair Values And Valuation Assumptions Used To Value Stock Option/SARs, ESPP, and Performance Units/Stock Stock-Based Compensation [Abstract]
Weighted Average Fair Value of Grants					$ 200.68		$ 134.09
Expected Volatility (in hundredths)					33.63%		36.39%
Risk-Free Interest Rate (in hundredths)					0.79%		0.39%
Share-Based Compensation Arrangement By Share Based Payment Award Stock Option/SARs, ESPP, Restricted Stock/Units and Performance Units/Stock [Abstract]
Unrecognized compensation expense	7.1				7.1
Weighted average period over which unrecognized compensation expense will be recognized (in years)					2 years 8 months 12 days
Restricted Stock/Restricted Stock Units and Performance Units/Performance Stock [Roll Forward]
Outstanding at January 1 (in shares)					71,000		0
Granted (in shares)					60,000		71,000
Released (in shares)					0		0
Forfeited (in shares)					0		0
Outstanding at September 30 (in shares)	131,000	[7]	71,000	[7]	131,000	[7]	71,000	[7]
Weighted Average Grant Price Restricted Stock and Restricted Stock Units/Performance Units and Performance Stock [Roll Forward]
Outstanding at January 1 (price per share)					$ 134.09		$ 0
Granted (price per share)					$ 200.68		$ 134.09
Released (price per share)					$ 0		$ 0
Forfeited (price per share)					$ 0		$ 0
Outstanding at September 30 (price per share)	$ 164.36	[7]	$ 134.09	[7]	$ 164.36	[7]	$ 134.09	[7]
Aggregate intrinsic value of stock and units outstanding	22.1		8.0		22.1		8.0
Performance Units and Performance Stock [Abstract]
Share-Based Compensation Arrangement By Performance Units and Performance Stock Compensation Cost	7.1		6.3		7.7		6.3
Lease And Well [Member]
Stock based compensation by job function [Line Items]
Compensation expense related to the company's stock-based compensation plans	7.2		9.9		25.4		26.4
Gathering And Processing Costs [Member]
Stock based compensation by job function [Line Items]
Compensation expense related to the company's stock-based compensation plans	0.3		0.3		0.9		0.8
Exploration Costs [Member]
Stock based compensation by job function [Line Items]
Compensation expense related to the company's stock-based compensation plans	6.7		7.4		20.6		20.3
General And Administrative [Member]
Stock based compensation by job function [Line Items]
Compensation expense related to the company's stock-based compensation plans	$ 31.3		$ 28.3		$ 56.3		$ 53.8

[1] The total intrinsic value of stock options/SARs exercised for the nine months ended September 30, 2013 and 2012 was $134.2 million and $110.8 million, respectively. The intrinsic value is based upon the difference between the market price of EOG's common stock on the date of exercise and the grant price of the stock options/SARs.

[2] The total intrinsic value of stock options/SARs outstanding at September 30, 2013 and 2012 was $332.3 million and $231.1 million, respectively. At September 30, 2013 and 2012, the weighted average remaining contractual life was 4.8 years and 4.1 years, respectively.

[3] The total intrinsic value of stock options/SARs vested or expected to vest at September 30, 2013 and 2012 was $322.5 million and $227.3 million, respectively. At September 30, 2013 and 2012, the weighted average remaining contractual life was 4.7 years and 4.0 years, respectively.

[4] The total intrinsic value of stock options/SARs exercisable at September 30, 2013 and 2012 was $202.4 million and $182.7 million, respectively. At September 30, 2013 and 2012, the weighted average remaining contractual life was 3.5 years and 2.7 years, respectively.

[5] The total intrinsic value of restricted stock and restricted stock units released for the nine months ended September 30, 2013 and 2012 was $89.2 million and $110.7 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.

[6] The total intrinsic value of restricted stock and restricted stock units outstanding at September 30, 2013 and 2012 was $637.0 million and $438.6 million, respectively.

[7] The total intrinsic value of performance units and performance stock outstanding at September 30, 2013 and 2012 was $22.1 million and $8.0 million, respectively.