Employee Benefit Plans (Details)			12 Months Ended
		Feb. 01, 2021 shares	Dec. 31, 2020 USD ($) $ / shares shares		Dec. 31, 2019 USD ($) $ / shares shares		Dec. 31, 2018 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense related to the company's stock-based compensation plans | $			$ 146,396,000		$ 174,738,000		$ 155,337,000
Common Shares Available for Grant			2,000,000.0
Share-based Payment Arrangement, Expense, Tax Benefit | $			$ (22,000,000)		(1,000,000)		20,000,000
Stock Options and Sars [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term of stock options and SARs granted			7 years
Share-based Compensation Expense Related To Stock Options, SAR and ESPP Grants | $			$ 62,000,000		$ 63,000,000		$ 60,000,000
Unrecognized compensation expense | $			$ 53,000,000
Stock Options/SARs Vested or Expected to Vest (in shares)			9,900,000
Intrinsic value of stock options/SARs vested or expected to vest | $			$ 22,500,000
Weighted Average Remaining Contractual Life for Stock Options/SARs Vested or Expected to Vest			4 years 2 months 12 days
Weighted average period over which unrecognized compensation expense will be recognized			2 years 1 month 6 days
Weighted average grant price for stock options/SARs vested or expected to vest (per share) | $ / shares			$ 84.76
Stock Options and SARs Rollforward [Abstract]
Outstanding at January 1 (in shares)			9,395,000		8,310,000		9,103,000
Granted (in shares)			1,996,000		1,965,000		1,906,000
Exercised (1) (in shares)	[1]		(23,000)		(606,000)		(2,493,000)
Forfeited (in shares)			(1,182,000)		(274,000)		(206,000)
Outstanding at December 31 (in shares)			10,186,000		9,395,000		8,310,000
Stock Options/SARs Exercisable at December 31 (in shares)			6,343,000		5,275,000		3,969,000
Intrinsic Value Of Stock Options/SARs Exercised During The Period | $			$ 400,000		$ 14,000,000		$ 118,000,000
Weighted Average Grant Price Stock Option and SARs [Rollfoward]
Outstanding at January 1 (in dollars per share) | $ / shares			$ 94.53		$ 96.90		$ 83.89
Granted (in dollars per share) | $ / shares			37.63		75.39		126.49
Exercised (in dollars per share) | $ / shares	[1]		69.59		61.43		72.21
Forfeited (in dollars per share) | $ / shares			88.93		102.57		94.43
Outstanding at December 31 (in dollars per share) | $ / shares			84.08		94.53		96.90
Stock Options/SARs Exercisable at December 31 (in dollars per share) | $ / shares			96.41		94.21		85.82
Weighted Average Fair Value And Valuation Assumptions Used To Value Stock Options/SARs, ESPP, and Performance Units/Stock-Based Compensation [Abstract]
Weighted Average Fair Value of Grants (price per share) | $ / shares			$ 11.06		$ 19.49		$ 33.46
Expected Volatility (in hundredths)			44.47%		32.02%		28.23%
Risk-Free Interest Rate (in hundredths)			0.21%		1.69%		2.68%
Dividend Yield (in hundredths)			3.27%		1.39%		0.72%
Expected Life (in years)			5 years 2 months 12 days		5 years 1 month 6 days		5 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			10,186,000
Weighted Average Remaining Life for Outstanding Options and SARs			4 years
Weighted Average Grant Price For Outstanding Options and SARs | $ / shares			$ 84.08
Aggregate Intrinsic Value For Outstanding Options and SARs | $	[2]		$ 24,578
Stock Options and SARs Exercisable			6,343,000
Weighted Average Remaining Life For Exercisable Units			3 years
Weighted Average Grant Price For Exercisable Options and SARs | $ / shares			$ 96.41
Aggregate Intrinsic Value For Exercisable Units | $	[2]		$ 124
Stock Options and Sars [Member] | Vesting Schedule - First Anniversary [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period Increments (in hundredths)			33.30%
Stock Options and Sars [Member] | Vesting Schedule - Second Anniversary [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period Increments (in hundredths)			33.30%
Stock Options and Sars [Member] | Vesting Schedule - Third Anniversary [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period Increments (in hundredths)			33.40%
ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Shares Available for Grant			1,900,000
Maximum Percentage Of Employee Pay Eligible For Contribution To ESPP Percentage			10.00%
Percentage of fair market value at which employees may purchase company stock via the ESPP			85.00%
Employee Stock Purchase Plan (ESPP) Disclosures [Abstract]
Aggregate Purchase Price | $			$ 16,103,000		$ 16,533,000		$ 14,887,000
Shares Purchased			377,000		224,000		180,000
Approximate Number of Participants			2,063		1,998		1,934
Weighted Average Fair Value And Valuation Assumptions Used To Value Stock Options/SARs, ESPP, and Performance Units/Stock-Based Compensation [Abstract]
Weighted Average Fair Value of Grants (price per share) | $ / shares			$ 19.14		$ 22.83		$ 25.75
Expected Volatility (in hundredths)			53.48%		34.78%		24.59%
Risk-Free Interest Rate (in hundredths)			0.90%		2.27%		1.89%
Dividend Yield (in hundredths)			2.27%		1.04%		0.64%
Expected Life (in years)			6 months		6 months		6 months
Restricted Stock and Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-Based Compensation Expense | $			$ 75,000,000		$ 97,000,000		$ 81,000,000
Intrinsic value released during the year | $			48,000,000		70,000,000		84,000,000
Aggregate intrinsic value of stock and unit outstanding | $			236,000,000		$ 381,000,000		$ 331,000,000
Unrecognized compensation expense | $			$ 178,000,000
Weighted average period over which unrecognized compensation expense will be recognized			1 year 7 months 6 days
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			3 years
Number of Shares and Units [Roll Forward]
Outstanding at January 1 (in shares)			4,546,000	[3]	3,792,000	[3]	3,905,000
Granted (in shares)			1,488,000		1,749,000		812,000
Released (in shares)	[4]		(1,213,000)		(855,000)		(740,000)
Forfeited (in shares)			(79,000)		(140,000)		(185,000)
Outstanding at December 31 (in shares)	[3]		4,742,000		4,546,000		3,792,000
Weighted Average Grant Fair Value [Abstract]
Outstanding at January 1 (in dollars per share) | $ / shares			$ 90.16	[3]	$ 96.64	[3]	$ 88.57
Granted (in dollars per share) | $ / shares			38.10		80.01		117.55
Released (in dollars per share) | $ / shares	[4]		85.92		96.93		78.16
Forfeited (in dollars per share) | $ / shares			86.52		97.54		92.12
Outstanding at December 31 (in dollars per share) | $ / shares	[3]		$ 74.97		$ 90.16		$ 96.64
Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense related to the company's stock-based compensation plans | $			$ 9,000,000		$ 15,000,000		$ 14,000,000
Intrinsic value released during the year | $			13,000,000		15,000,000		18,000,000
Aggregate intrinsic value of stock and unit outstanding | $			31,000,000		$ 50,000,000		$ 47,000,000
Unrecognized compensation expense | $			$ 5,000,000
Weighted average period over which unrecognized compensation expense will be recognized			1 year 10 months 24 days
Cliff Vesting Period			41 months
Number of Shares and Units [Roll Forward]
Outstanding at January 1 (in shares)			598,000	[5]	539,000	[5]	502,000
Granted (in shares)			172,000		172,000		113,000
Granted for Performance Multiple (1) (in shares)	[6]		66,000		72,000		72,000
Released (in shares)	[7]		(223,000)		(185,000)		(148,000)
Forfeited (in shares)			0		0		0
Outstanding at December 31 (in shares)	[5]		613,000	[8]	598,000		539,000
Weighted Average Grant Fair Value [Abstract]
Outstanding at January 1 (in dollars per share) | $ / shares			$ 92.19	[5]	$ 101.53	[5]	$ 90.96
Granted (in dollars per share) | $ / shares			37.44		75.09		125.73
Granted for Performance Multiple (1) (in dollars per share) | $ / shares	[6]		100.95		69.43		101.87
Released (in dollars per share) | $ / shares	[7]		88.52		94.63		84.43
Forfeited (in dollars per share) | $ / shares			0		0		0
Outstanding at December 31 (in dollars per share) | $ / shares	[5]		79.10		92.19		101.53
Weighted Average Fair Value And Valuation Assumptions Used To Value Stock Options/SARs, ESPP, and Performance Units/Stock-Based Compensation [Abstract]
Weighted Average Fair Value of Grants (price per share) | $ / shares			$ 42.77		$ 79.98		$ 136.74
Expected Volatility (in hundredths)			47.27%		29.20%		29.92%
Risk-Free Interest Rate (in hundredths)			0.16%		1.51%		2.85%
Performance Units and Performance Stock [Abstract]
performance period for performance units			3 years
Minimum Performance Multiple at the Completion Performance Period			0.00%
Maximum Performance Multiple at the Completion Performance Period			200.00%
Performance Multiple Applied at the Completion Period		125.00%	150.00%		200.00%		200.00%
Minimum Performance Units and Stock Allowed to be Outstanding			77
Maximum Performance Units and Stock Allowed to be Outstanding			1,149
Maximum Performance Multiple Applied at the Completion Period					200.00%		200.00%
Additional Performance Awards Granted		19,629
Pension Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total pension plan costs | $			$ 46,000,000		$ 51,000,000		$ 43,000,000
Company contributions to foreign pension plans | $			1,000,000		1,000,000		1,000,000
Defined Benefit Plan, Benefit Obligation | $			13,000,000		12,000,000
Fair value of foreign pension plan assets | $			12,000,000		10,000,000
Accrued benefit cost | $			(100,000)		(100,000)
Lease And Well [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense related to the company's stock-based compensation plans | $			52,000,000		56,000,000		51,000,000
Gathering And Processing Costs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [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]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense related to the company's stock-based compensation plans | $			21,000,000		26,000,000		25,000,000
General And Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense related to the company's stock-based compensation plans | $			$ 72,000,000		$ 92,000,000		$ 78,000,000
$ 34.00 to $  43.99 | Stock Options and Sars [Member]
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			1,974,000
Weighted Average Remaining Life for Outstanding Options and SARs			7 years
Weighted Average Grant Price For Outstanding Options and SARs | $ / shares			$ 37.43
Stock Options and SARs Exercisable			10,000
Weighted Average Remaining Life For Exercisable Units			1 year
Weighted Average Grant Price For Exercisable Options and SARs | $ / shares			$ 37.44
44.00 to     74.99 | Stock Options and Sars [Member]
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			872,000
Weighted Average Remaining Life for Outstanding Options and SARs			2 years
Weighted Average Grant Price For Outstanding Options and SARs | $ / shares			$ 69.37
Stock Options and SARs Exercisable			846,000
Weighted Average Remaining Life For Exercisable Units			2 years
Weighted Average Grant Price For Exercisable Options and SARs | $ / shares			$ 69.47
75.00 to     75.99 | Stock Options and Sars [Member]
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			1,863,000
Weighted Average Remaining Life for Outstanding Options and SARs			6 years
Weighted Average Grant Price For Outstanding Options and SARs | $ / shares			$ 75.09
Stock Options and SARs Exercisable			636,000
Weighted Average Remaining Life For Exercisable Units			5 years
Weighted Average Grant Price For Exercisable Options and SARs | $ / shares			$ 75.09
76.00 to     95.99 | Stock Options and Sars [Member]
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			1,242,000
Weighted Average Remaining Life for Outstanding Options and SARs			3 years
Weighted Average Grant Price For Outstanding Options and SARs | $ / shares			$ 94.47
Stock Options and SARs Exercisable			1,215,000
Weighted Average Remaining Life For Exercisable Units			3 years
Weighted Average Grant Price For Exercisable Options and SARs | $ / shares			$ 94.63
96.00 to   101.99 | Stock Options and Sars [Member]
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			2,477,000
Weighted Average Remaining Life for Outstanding Options and SARs			3 years
Weighted Average Grant Price For Outstanding Options and SARs | $ / shares			$ 97.95
Stock Options and SARs Exercisable			2,457,000
Weighted Average Remaining Life For Exercisable Units			3 years
Weighted Average Grant Price For Exercisable Options and SARs | $ / shares			$ 97.95
102.00 to   129.99 | Stock Options and Sars [Member]
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			1,758,000
Weighted Average Remaining Life for Outstanding Options and SARs			5 years
Weighted Average Grant Price For Outstanding Options and SARs | $ / shares			$ 126.44
Stock Options and SARs Exercisable			1,179,000
Weighted Average Remaining Life For Exercisable Units			5 years
Weighted Average Grant Price For Exercisable Options and SARs | $ / shares			$ 126.37

[1] The total intrinsic value of stock options/SARs exercised during the years 2020, 2019 and 2018 was $0.4 million, $14 million and $118 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.

[2] 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, in thousands.

[3] The total intrinsic value of restricted stock and restricted stock units outstanding at December 31, 2020, 2019 and 2018 was $236 million, $381 million and $331 million, respectively. The intrinsic value is based on the closing market price of the Common Stock on the last trading day of the year.

[4] The total intrinsic value of restricted stock and restricted stock units released during the years ended December 31, 2020, 2019 and 2018 was $48 million, $70 million and $84 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.

[5] The total intrinsic value of Performance Awards outstanding at December 31, 2020, 2019 and 2018 was $31 million, $50 million and $47 million, respectively. The intrinsic value is based on the closing market price of the Common Stock on the last trading day of the year.

[6] Upon completion of the Performance Period for the Performance Awards granted in 2016, 2015 and 2014, a performance multiple of 150%, 200% and 200%, respectively, was applied to each of the grants resulting in additional grants of Performance Awards in February 2020, 2019 and 2018.

[7] The total intrinsic value of Performance Awards released during the years ended December 31, 2020, 2019 and 2018 was $13 million, $15 million and $18 million, respectively. The intrinsic value is based upon the closing price of EOG's common stock on the date Performance Awards are released.

[8] Upon the application of the relevant performance multiple at the completion of each of the remaining Performance Periods, a minimum of 77 and a maximum of 1,149 Performance Awards could be outstanding.