Stock-Based Payments (Details) - USD ($)		3 Months Ended			9 Months Ended
		Sep. 30, 2021		Sep. 30, 2020	Sep. 30, 2021		Sep. 30, 2020
Stock Options/SARs, Employee Stock Purchase Plan (ESPP), Restricted Stock and Restricted Stock Units and Performance Units Disclosures [Line Items]
Stock-Based Compensation Expenses		$ 51,000,000		$ 33,000,000	$ 117,000,000		$ 113,000,000
Common Shares Available for Grant		17,000,000			17,000,000
Aggregate Maximum of Common Shares		20,000,000			20,000,000
Stock Options And SARs
Stock Options/SARs, Employee Stock Purchase Plan (ESPP), Restricted Stock and Restricted Stock Units and Performance Units Disclosures [Line Items]
Stock-based compensation expense related to stock options, SAR and ESPP grants		$ 20,000,000		$ 23,000,000	$ 39,000,000		$ 52,000,000
Unrecognized compensation expense		$ 69,000,000			$ 69,000,000
Weighted average period over which unrecognized compensation expense will be recognized (in years)					2 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)					$ 24.92		$ 11.06
Expected Volatility (in hundredths)					42.24%		44.46%
Risk-Free Interest Rate (in hundredths)					0.50%		0.21%
Dividend Yield (in hundredths)					2.25%		3.27%
Expected Life (in years)					5 years 2 months 12 days		5 years 2 months 12 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at January 1 (in shares)					10,186,000		9,395,000
Granted (in shares)					1,976,000		1,993,000
Exercised (1) (in shares)	[1]				(448,000)		(23,000)
Forfeited (in shares)					(984,000)		(1,077,000)
Outstanding at September 30 (2)	[2]	10,730,000		10,288,000	10,730,000		10,288,000
Stock Options and SARs Vested or Expected to Vest (3) (in shares)	[3]	10,407,000		9,963,000	10,407,000		9,963,000
Stock Options and SARs Exercisable at March 31 (4) (in shares)	[4]	6,906,000		6,389,000	6,906,000		6,389,000
Intrinsic Value of Stock Options/SARs Exercised	[1]				$ 8,000,000		$ 400,000
Intrinsic Value of Stock Options/SARs Outstanding	[2]	$ 95,000,000		$ 10,000.00	$ 95,000,000		$ 10,000.00
Weighted Average Remaining Contractual Life for Stock Options/SARs Outstanding (in years)	[2]				4 years 3 months 18 days		4 years 6 months
Intrinsic Value of Stock Options/SARs Vested or Expected to Vest	[3]	90,000,000		10,000.00	$ 90,000,000		$ 10,000.00
Weighted average remaining contractual life for stock options/SARs vested or expected to vest (in years)	[3]				4 years 3 months 18 days		4 years 6 months
Aggregate Intrinsic Value for Exercisable Units	[4]	$ 38,000,000		$ 0	$ 38,000,000		$ 0
Weighted average remaining contractual life for exercisable options/SARs (in years)	[4]				3 years 2 months 12 days		3 years 4 months 24 days
Weighted Average Grant Price Stock Option and SARs [Rollforward]
Outstanding at January 1 (price per share)					$ 84.08		$ 94.53
Granted (price per share)					81.66		37.62
Exercised (1) (price per share)	[1]				64.18		69.59
Forfeited (price per share)					98.64		88.54
Outstanding at September 30 (2) (price per share)	[2]	$ 83.13		$ 84.19	83.13		84.19
Vested or Expected to Vest (3) (price per share)	[3]	83.65		84.86	83.65		84.86
Exercisable at September 30 (4) (price per share)	[4]	$ 92.39		$ 96.53	92.39		96.53
ESPP
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)					$ 18.15		$ 18.96
Expected Volatility (in hundredths)					51.23%		55.53%
Risk-Free Interest Rate (in hundredths)					0.07%		0.83%
Dividend Yield (in hundredths)					2.88%		2.35%
Expected Life (in years)					6 months		6 months
Restricted Stock And Restricted Stock Units
Stock Options/SARs, Employee Stock Purchase Plan (ESPP), Restricted Stock and Restricted Stock Units and Performance Units Disclosures [Line Items]
Unrecognized compensation expense		$ 224,000,000			$ 224,000,000
Weighted average period over which unrecognized compensation expense will be recognized (in years)					1 year 9 months 18 days
Share-Based Compensation Arrangement By Restricted Stock And Restricted Stock Units Compensation Cost		$ 20,000,000		$ 4,000,000	$ 65,000,000		$ 53,000,000
Restricted Stock/Restricted Stock Units and Performance Units [Roll Forward]
Outstanding at January 1 (in shares)					4,742,000		4,546,000
Granted (in shares)					1,409,000		1,440,000
Released (1) (in shares)	[5]				(1,321,000)		(1,139,000)
Forfeited (in shares)					(65,000)		(63,000)
Outstanding at September 30 (3)	[6]	4,765,000		4,784,000	4,765,000		4,784,000
Intrinsic value released during the year	[5]				$ 104,000,000		$ 45,000,000
Aggregate intrinsic value of stock and units outstanding	[6]	$ 383,000,000		$ 172,000,000	$ 383,000,000		$ 172,000,000
Weighted Average Grant Price Restricted Stock and Restricted Stock Units [Roll Forward]
Outstanding at January 1 (price per share)					$ 74.97		$ 90.16
Granted (price per share)					81.44		38.16
Released (2) (price per share)	[5]				101.63		85.94
Forfeited (price per share)					68.49		90.00
Outstanding at September 30 (3) (price per share)	[6]	$ 69.58		$ 75.51	$ 69.58		$ 75.51
Performance Unit
Stock Options/SARs, Employee Stock Purchase Plan (ESPP), Restricted Stock and Restricted Stock Units and Performance Units Disclosures [Line Items]
Stock-Based Compensation Expenses		$ 11,000,000		$ 6,000,000	$ 13,000,000		$ 8,000,000
Unrecognized compensation expense		$ 15,000,000			$ 15,000,000
Weighted average period over which unrecognized compensation expense will be recognized (in years)					2 years 1 month 6 days
Restricted Stock/Restricted Stock Units and Performance Units [Roll Forward]
Outstanding at January 1 (in shares)					613,000		598,000
Granted (in shares)					222,000		172,000
Granted for Performance Multiple (1) (in shares)	[7]				19,000		66,000
Released (1) (in shares)	[8]				(175,000)		(223,000)
Forfeited (in shares)					0		0
Outstanding at September 30 (3)	[9]	679,000	[10]	613,000	679,000	[10]	613,000
Intrinsic value released during the year					$ 13,000,000	[8]	$ 13,000,000
Aggregate intrinsic value of stock and units outstanding	[9]	$ 55,000,000		$ 22,000,000	$ 55,000,000		$ 22,000,000
Weighted Average Grant Price Restricted Stock and Restricted Stock Units [Roll Forward]
Outstanding at January 1 (price per share)					$ 88.38		$ 103.91
Granted (price per share)					90.94		42.77
Granted for Performance Multiple (1) (in dollars per share)	[7]				113.81		119.10
Released (2) (price per share)	[8]				113.06		103.87
Forfeited (price per share)					0		0
Outstanding at September 30 (3) (price per share)	[9]	$ 83.59		$ 88.38	$ 83.59		$ 88.38
Performance Units and Performance Stock Disclosures [Abstract]
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%
Performance Multiple Applied at the Completion Period	[7]				125.00%		150.00%
Minimum Performance Units and Stock Allowed to be Outstanding	[10]				0
Maximum Performance Units Allowed to be Outstanding	[10]				1,358
Lease and Well
Stock Options/SARs, Employee Stock Purchase Plan (ESPP), Restricted Stock and Restricted Stock Units and Performance Units Disclosures [Line Items]
Stock-Based Compensation Expenses		$ 11,000,000		$ 9,000,000	$ 36,000,000		$ 39,000,000
Gathering and Processing Costs
Stock Options/SARs, Employee Stock Purchase Plan (ESPP), Restricted Stock and Restricted Stock Units and Performance Units Disclosures [Line Items]
Stock-Based Compensation Expenses		1,000,000		0	2,000,000		1,000,000
Exploration Costs
Stock Options/SARs, Employee Stock Purchase Plan (ESPP), Restricted Stock and Restricted Stock Units and Performance Units Disclosures [Line Items]
Stock-Based Compensation Expenses		4,000,000		1,000,000	15,000,000		15,000,000
General and Administrative
Stock Options/SARs, Employee Stock Purchase Plan (ESPP), Restricted Stock and Restricted Stock Units and Performance Units Disclosures [Line Items]
Stock-Based Compensation Expenses		$ 35,000,000		$ 23,000,000	$ 64,000,000		$ 58,000,000

[1] The total intrinsic value of stock options/SARs exercised during the nine months ended September 30, 2021 and 2020 was $8 million and $0.4 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 exercise price of the stock options/SARs.

[2] The total intrinsic value of stock options/SARs outstanding at September 30, 2021 and 2020 was $95 million and $0.01 million, respectively. At September 30, 2021 and 2020, the weighted average remaining contractual life was 4.3 years and 4.5 years, respectively.

[3] The total intrinsic value of stock options/SARs vested or expected to vest at September 30, 2021 and 2020 was $90 million and $0.01 million, respectively. At September 30, 2021 and 2020, the weighted average remaining contractual life was 4.3 years and 4.5 years, respectively.

[4] The total intrinsic value of stock options/SARs exercisable at September 30, 2021 and 2020 was $38 million and zero, respectively. At September 30, 2021 and 2020, the weighted average remaining contractual life was 3.2 years and 3.4 years, respectively.

[5] The total intrinsic value of restricted stock and restricted stock units released during the nine months ended September 30, 2021 and 2020 was $104 million and $45 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, 2021 and 2020 was $383 million and $172 million, respectively.

[7] Upon completion of the Performance Period for the Performance Units granted in 2017 and 2016, a performance multiple of 125% and 150%, respectively, was applied to each of the grants resulting in additional grants of Performance Units in February 2021 and February 2020, respectively.

[8] The total intrinsic value of Performance Units released was $13 million for both the nine months ended September 30, 2021 and 2020. The intrinsic value is based upon the closing price of EOG's common stock on the date the Performance Units are released.

[9] The total intrinsic value of Performance Units outstanding at September 30, 2021 and 2020 was approximately $55 million and $22 million, respectively.

[10] Upon the application of the relevant performance multiple at the completion of each of the remaining Performance Periods, a minimum of zero and a maximum of 1,358 Performance Units could be outstanding.