Segment Information (Details) - USD ($)		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Schedule of Segment Reporting Information By Segment [Abstract]
Operating Revenues and Other		$ 4,765,000,000	$ 2,246,000,000	$ 12,598,000,000	$ 8,067,000,000
Operating Income (Loss)		1,471,000,000	(3,000,000)	3,574,000,000	(1,032,000,000)
Other Income, Net		6,000,000	3,000,000	0	17,000,000
Interest Expense, Net		(48,000,000)	(53,000,000)	(140,000,000)	(152,000,000)
Income (Loss) Before Income Taxes		1,429,000,000	(53,000,000)	3,434,000,000	(1,167,000,000)
Total Assets		37,172,000,000		37,172,000,000		$ 35,805,000,000
United States
Schedule of Segment Reporting Information By Segment [Abstract]
Operating Revenues and Other		4,692,000,000	2,196,000,000	12,293,000,000	7,913,000,000
Operating Income (Loss)	[1]	1,455,000,000	(16,000,000)	3,422,000,000	(990,000,000)
Total Assets		36,330,000,000		36,330,000,000		35,048,000,000
Pretax Impairment Charges for Proved Oil and Gas Properties and Other Property, Plant and Equipment			26,000,000		1,488,000,000
Pretax Impairment Changes For Other Assets			1,000,000		220,000,000
Trinidad
Schedule of Segment Reporting Information By Segment [Abstract]
Operating Revenues and Other		72,000,000	35,000,000	229,000,000	111,000,000
Operating Income (Loss)		37,000,000	12,000,000	121,000,000	35,000,000
Total Assets		597,000,000		597,000,000		546,000,000
Other International
Schedule of Segment Reporting Information By Segment [Abstract]
Operating Revenues and Other	[2]	1,000,000	15,000,000	76,000,000	43,000,000
Operating Income (Loss)	[2],[3]	(21,000,000)	1,000,000	31,000,000	(77,000,000)
Total Assets	[4]	245,000,000		245,000,000		$ 211,000,000
Pretax Impairment Charges for Proved Oil and Gas Properties and Other Property, Plant and Equipment		$ 13,000,000	$ 0	$ 15,000,000	$ 79,000,000

[1] EOG recorded pretax impairment charges of $26 million and $1,488 million for the three and nine months ended September 30, 2020, respectively, for proved oil and gas properties, leasehold costs and other assets due to the decline in commodity prices and revisions of asset retirement obligations for certain properties. See Note 11. In addition, EOG recorded pretax impairment charges of $1 million and $220 million for the three and nine months ended September 30, 2020, respectively, for sand and crude-by-rail assets.

[2] Other International primarily consists of EOG's China and Canada operations. The China operations were sold in the second quarter of 2021. EOG began exploration programs in Australia in the third quarter of 2021 and in Oman in the third quarter of 2020.

[3] EOG recorded pretax impairment charges of $13 million and zero for the three months ended September 30, 2021 and 2020, respectively, and $15 million and $79 million for the nine months ended September 30, 2021 and 2020, respectively, for proved oil and gas properties and firm commitment contracts related to its decision to exit the Horn River Basin in British Columbia, Canada.

[4] Other International primarily consists of EOG's China and Canada operations. The China operations were sold in the second quarter of 2021. EOG began exploration programs in Australia in the third quarter of 2021 and in Oman in the third quarter of 2020.