Unaudited Quarterly Financial Information (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2017		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Operating Revenues and Other	$ 4,574,536		$ 4,781,624		$ 4,238,077		$ 3,681,162		$ 3,340,439		$ 2,644,844		$ 2,612,472		$ 2,610,565		$ 17,275,399	$ 11,208,320	$ 7,650,632	[1]
Operating Income	1,123,140		1,506,687		964,931		874,588		475,912		214,836		127,908		107,746		4,469,346	926,402	(1,225,281)
Income (Loss) Before Income Taxes	1,088,340		1,446,363		892,936		813,359		413,353		145,980		62,467		39,382
Income Tax Provision (Benefit)	195,572		255,411		196,205		174,770		(2,017,115)	[2]	45,439	[2]	39,414	[2]	10,865	[2]	821,958	(1,921,397)	(460,819)
Net Income (Loss)	$ 892,768		$ 1,190,952		$ 696,731		$ 638,589		$ 2,430,468		$ 100,541		$ 23,053		$ 28,517		$ 3,419,040	$ 2,582,579	$ (1,096,686)
Net Income (Loss) Per Share
Basic (in dollars per share)	$ 1.55	[3]	$ 2.06	[3]	$ 1.21	[3]	$ 1.11	[3]	$ 4.22	[3]	$ 0.17	[3]	$ 0.04	[3]	$ 0.05	[3]	$ 5.93	$ 4.49	$ (1.98)
Diluted (in dollars per share)	$ 1.54	[3]	$ 2.05	[3]	$ 1.20	[3]	$ 1.10	[3]	$ 4.20	[3]	$ 0.17	[3]	$ 0.04	[3]	$ 0.05	[3]	$ 5.89	$ 4.46	$ (1.98)
Average Number of Common Shares [Abstract]
Basic (in shares)	577,035		577,254		576,135		575,775		575,394		574,783		574,439		573,935		576,578	574,620	553,384
Diluted (in shares)	580,288		581,559		580,375		579,726		579,203		578,736		578,483		578,593		580,441	578,693	553,384
Provisional Reduction in the Income Tax Provision																		$ 2,200,000

[1] EOG had sales activity with three significant purchasers in 2016, one totaling $1.2 billion, one totaling $1.1 billion and one totaling $1.0 billion of consolidated Operating Revenues and Other in the United States segment.

[2] Includes an income tax benefit of approximately $2.2 billion for the quarter ended December 31, 2017, primarily due to the enactment of the Tax Cuts and Jobs Act in December 2017. See Note 6 to the Consolidated Financial Statements.

[3] The sum of quarterly net income per share may not agree with total year net income per share as each quarterly computation is based on the weighted average of common shares outstanding.