Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Stock Options/SARs and Employee Stock Purchase Plan (ESPP) Disclosures [Line Items]
Common Shares Available for Grant		21,400,000		21,400,000
Compensation expense related to the company's stock-based compensation plans		$ 37.6	$ 40.3	$ 97.1	$ 102.0
Stock Options and SARs [Member]
Stock Options/SARs and Employee Stock Purchase Plan (ESPP) Disclosures [Line Items]
Unrecognized compensation expense		106.1		$ 106.1
Weighted average period over which unrecognized compensation expense will be recognized (in years)				3 years
Stock-based compensation expense related to stock options, SAR and ESPP grants		$ 18.8	$ 20.0	$ 45.0	$ 43.3
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 (price per share)				$ 25.77	$ 21.87
Expected Volatility (in hundredths)				31.52%	38.04%
Risk-Free Interest Rate (in hundredths)				0.78%	0.83%
Dividend Yield (in hundredths)				0.76%	0.85%
Expected Life (in years)				5 years 4 months 24 days	5 years 3 months 18 days
Stock Options and SARs Rollforward [Abstract]
Outstanding at January 1 (in shares)				10,744,000	10,493,000
Granted (in shares)				1,821,000	2,029,000
Exercised (1) (in shares)	[1]			(1,673,000)	(1,291,000)
Forfeited (in shares)				(241,000)	(203,000)
Outstanding at September 30 (2) (in shares)	[2]	10,651,000	11,028,000	10,651,000	11,028,000
Stock Options and SARs Vested or Expected to Vest (in shares)	[3]	10,300,000	10,653,000	10,300,000	10,653,000
Stock Options and SARs Exercisable at September 30 (in shares)	[4]	6,302,000	6,121,000	6,302,000	6,121,000
Weighted Average Grant Price Stock Option and SARs [Rollforward]
Outstanding at January 1 (price per share)				$ 67.98	$ 64.96
Granted (price per share)				94.87	69.95
Exercised (1) (price per share)	[1]			49.85	47.25
Forfeited (price per share)				85.77	80.12
Outstanding at September 30 (2) (price per share)	[2]	$ 75.02	$ 67.67	75.02	67.67
Weighted average grant price for stock options/SARs vested or expected to vest (price per share)	[3]	74.60	67.22	74.60	67.22
Stock Options and SARs Exercisable at September 30 (price per share)	[4]	$ 66.46	$ 57.34	66.46	57.34
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 (price per share)				$ 19.28	$ 21.40
Expected Volatility (in hundredths)				36.54%	32.54%
Risk-Free Interest Rate (in hundredths)				0.43%	0.12%
Dividend Yield (in hundredths)				0.82%	0.72%
Expected Life (in years)				6 months	6 months
Restricted Stock And Restricted Stock Units [Member]
Stock Options/SARs and Employee Stock Purchase Plan (ESPP) Disclosures [Line Items]
Unrecognized compensation expense		$ 170.3		$ 170.3
Weighted average period over which unrecognized compensation expense will be recognized (in years)				2 years 9 months 18 days
Share-Based Compensation Arrangement By Restricted Stock And Restricted Stock Units Compensation Cost		$ 13.1	$ 16.2	$ 45.5	$ 53.9
Restricted Stock/Restricted Stock Units and Performance Units/Performance Stock [Roll Forward]
Outstanding at January 1 (in shares)				4,908,000	5,394,000
Granted (in shares)				833,000	1,036,000
Released (1) (in shares)	[5]			(1,392,000)	(1,250,000)
Forfeited (in shares)				(269,000)	(152,000)
Outstanding at September 30 (2) (in shares)	[6]	4,080,000	5,028,000	4,080,000	5,028,000
Weighted Average Grant Price Restricted Stock and Restricted Stock Units/Performance Units and Performance Stock [Roll Forward]
Outstanding at January 1 (price per share)				$ 70.35	$ 64.39
Granted (price per share)				87.76	77.90
Released (1) (price per share)	[5]			53.15	51.02
Forfeited (price per share)				76.40	74.83
Outstanding at September 30 (2) (price per share)	[6]	$ 79.37	$ 70.18	$ 79.37	70.18
Performance Units and Performance Stock [Member]
Stock Options/SARs and Employee Stock Purchase Plan (ESPP) Disclosures [Line Items]
Unrecognized compensation expense		$ 7.4		$ 7.4
Weighted average period over which unrecognized compensation expense will be recognized (in years)				3 years 3 months 18 days
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 (price per share)				$ 112.09	$ 80.64
Expected Volatility (in hundredths)				32.01%	29.35%
Risk-Free Interest Rate (in hundredths)				0.89%	1.07%
Term Of Zero- Coupon Risk- Free Interest Rate In Years Derived From Treasury Constant Maturities Yield Curve				3 years 3 months
Restricted Stock/Restricted Stock Units and Performance Units/Performance Stock [Roll Forward]
Outstanding at January 1 (in shares)				405,000
Granted (in shares)				71,805
Released (1) (in shares)				(134,016)
Outstanding at September 30 (2) (in shares)		485,345		485,345
Weighted Average Grant Price Restricted Stock and Restricted Stock Units/Performance Units and Performance Stock [Roll Forward]
Aggregate intrinsic value of stock and units outstanding		$ 46.9		$ 46.9
Intrinsic value of stock and units released during the year				$ 9.7
Performance Units and Performance Stock [Abstract]
Additional Performance Awards Granted				142,556
Minimum Performance Units and Stock Allowed to be Outstanding				151,096
Share-Based Compensation Arrangement By Performance Units and Performance Stock Compensation Cost		5.7	$ 4.1	$ 6.6	$ 4.8
Maximum Performance Units and Stock Allowed to be Outstanding				819,594
Maximum Vest Period from the Date of Grant				5 years
Performance Period for Performance units and shares				3 years
Minimum Performance Multiple at the Completion of the Performance Period				0.00%
Maximum Performance Multiple at the Completion of the Performance Period				200.00%
Lease And Well [Member]
Stock Options/SARs and Employee Stock Purchase Plan (ESPP) Disclosures [Line Items]
Compensation expense related to the company's stock-based compensation plans		8.9	10.3	$ 28.2	32.9
Gathering And Processing Costs [Member]
Stock Options/SARs and Employee Stock Purchase Plan (ESPP) Disclosures [Line Items]
Compensation expense related to the company's stock-based compensation plans		0.4	0.4	1.0	1.0
Exploration Costs [Member]
Stock Options/SARs and Employee Stock Purchase Plan (ESPP) Disclosures [Line Items]
Compensation expense related to the company's stock-based compensation plans		4.1	6.0	15.6	19.3
General And Administrative [Member]
Stock Options/SARs and Employee Stock Purchase Plan (ESPP) Disclosures [Line Items]
Compensation expense related to the company's stock-based compensation plans		$ 24.2	$ 23.6	$ 52.3	$ 48.8

[1] The total intrinsic value of stock options/SARs exercised for the nine months ended September 30, 2016 and 2015 was $58.7 million and $52.4 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, 2016 and 2015 was $240.8 million and $136.9 million, respectively. At September 30, 2016 and 2015, the weighted average remaining contractual life was 4.1 years and 4.4 years, respectively.

[3] The total intrinsic value of stock options/SARs vested or expected to vest at September 30, 2016 and 2015 was $237.2 million and $135.7 million, respectively. At September 30, 2016 and 2015, the weighted average remaining contractual life was 4.0 years and 4.3 years, respectively.

[4] The total intrinsic value of stock options/SARs exercisable at September 30, 2016 and 2015 was $196.3 million and $121.6 million, respectively. At September 30, 2016 and 2015, the weighted average remaining contractual life was 2.8 years and 3.1 years, respectively.

[5] The total intrinsic value of restricted stock and restricted stock units released for the nine months ended September 30, 2016 and 2015 was $116.3 million and $102.5 million, respectively. The intrinsic value is based upon the closing price of EOG's common stock on the date the restricted stock and restricted stock units are released.

[6] The total intrinsic value of restricted stock and restricted stock units outstanding at September 30, 2016 and 2015 was $394.6 million and $366.0 million, respectively.