Oil and Gas Exploration and Production Industries Disclosures, Discounted Future Net Cash Flows (Details) $ in Thousands		12 Months Ended
		Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2020 USD ($)		Dec. 31, 2019 USD ($)		Dec. 31, 2018 USD ($)
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Future cash inflows					$ 74,909,366	[1]	$ 121,478,362	[2]	$ 134,119,690	[3]
Future production costs					(34,826,068)		(42,641,887)		(42,654,642)
Future development costs					(15,404,203)		(20,586,449)		(16,667,893)
Future income taxes					(4,442,257)		(11,565,498)		(14,962,141)
Future net cash flows					20,236,838		46,684,528		59,835,014
Discount to present value at 10% annual rate					(8,546,826)		(21,163,763)		(27,409,059)
Standardized measure of discounted future net cash flows relating to proved oil and gas reserves		$ 11,690,012	$ 32,425,955	$ 32,425,955	11,690,012		25,520,765		32,425,955
Annual Rate of Discount to Present Value		10.00%	10.00%	10.00%
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Balance at Beginning of Period		$ 25,520,765	$ 32,425,955	$ 18,327,660
Sales and transfers of oil and gas produced, net of production costs		(4,579,174)	(8,210,438)	(8,734,622)
Net changes in prices and production costs		(18,445,993)	(10,880,447)	12,856,429
Extensions, discoveries, additions and improved recovery, net of related costs		1,501,373	5,709,558	8,430,953
Development costs incurred		1,674,800	3,032,150	2,745,160
Revisions of estimated development cost		4,137,607	(738,024)	(410,525)
Revisions of previous quantity estimates		(3,297,312)	(695,521)	(101,726)
Accretion of discount		3,104,368	3,949,758	2,042,622
Net change in income taxes		3,488,199	1,548,707	(4,973,058)
Purchases of reserves in place		49,232	98,539	116,887
Sales of reserves in place		(156,293)	(50,651)	(117,932)
Changes in timing and other		(1,307,560)	(668,821)	2,244,107
Balance at End of Period		11,690,012	25,520,765	32,425,955
United States
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Future cash inflows					73,726,893	[1]	120,359,769	[2]	133,066,375	[3]
Future production costs					(34,618,860)		(42,387,801)		(42,351,174)
Future development costs					(15,159,373)		(20,355,746)		(16,577,794)
Future income taxes					(4,336,578)		(11,459,567)		(14,756,011)
Future net cash flows					19,612,082		46,156,655		59,381,396
Discount to present value at 10% annual rate					(8,410,282)		(21,042,593)		(27,348,744)
Standardized measure of discounted future net cash flows relating to proved oil and gas reserves		25,114,062	32,032,652	32,032,652	$ 11,201,800		$ 25,114,062		$ 32,032,652
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Balance at Beginning of Period		25,114,062	32,032,652	17,756,935
Sales and transfers of oil and gas produced, net of production costs		(4,381,840)	(7,955,115)	(8,416,853)
Net changes in prices and production costs		(18,624,768)	(10,973,981)	12,750,466
Extensions, discoveries, additions and improved recovery, net of related costs		1,436,988	5,608,038	8,418,666
Development costs incurred		1,674,800	3,003,510	2,732,560
Revisions of estimated development cost		4,148,768	(597,869)	(410,741)
Revisions of previous quantity estimates		(3,307,180)	(812,781)	(173,084)
Accretion of discount		3,054,437	3,891,701	1,967,592
Net change in income taxes		3,497,362	1,454,050	(4,965,373)
Purchases of reserves in place		49,232	98,539	116,887
Sales of reserves in place		(156,293)	(50,651)	(35,874)
Changes in timing and other		(1,303,768)	(584,031)	2,291,471
Balance at End of Period		11,201,800	25,114,062	32,032,652
United States | Crude Oil
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Per unit price used to calculate future cash inflows					37.19		57.51		68.54
United States | Natural Gas Liquids [Member]
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Per unit price used to calculate future cash inflows					12.47		16.91		27.83
United States | Natural Gas
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Per unit price used to calculate future cash inflows					1.45		2.07		2.50
Trinidad
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Future cash inflows					$ 900,815	[1]	$ 813,102	[2]	$ 749,695	[3]
Future production costs					(153,275)		(166,705)		(204,444)
Future development costs					(226,430)		(212,303)		(78,199)
Future income taxes					(81,368)		(73,508)		(174,382)
Future net cash flows					439,742		360,586		292,670
Discount to present value at 10% annual rate					(100,350)		(86,009)		(26,832)
Standardized measure of discounted future net cash flows relating to proved oil and gas reserves		339,392	265,838	332,427	$ 339,392		$ 274,577		$ 265,838
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Balance at Beginning of Period		274,577	265,838	332,427
Sales and transfers of oil and gas produced, net of production costs		(151,979)	(235,404)	(265,370)
Net changes in prices and production costs		131,859	65,962	84,353
Extensions, discoveries, additions and improved recovery, net of related costs		64,385	85,233	0
Development costs incurred		0	22,820	0
Revisions of estimated development cost		(11,161)	(129,047)	4,030
Revisions of previous quantity estimates		11,632	116,062	39,608
Accretion of discount		34,624	43,148	50,191
Net change in income taxes		(12,185)	93,975	3,844
Purchases of reserves in place		0	0	0
Sales of reserves in place		0	0	0
Changes in timing and other		(2,360)	(54,010)	16,755
Balance at End of Period		339,392	274,577	265,838
Trinidad | Crude Oil
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Per unit price used to calculate future cash inflows					26.75		46.77		55.66
Trinidad | Natural Gas
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Per unit price used to calculate future cash inflows					3.28		2.90		3.06
Other International (1)
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Future cash inflows	[4]				$ 281,658	[1]	$ 305,491	[2]	$ 303,620	[3]
Future production costs	[4]				(53,933)		(87,381)		(99,024)
Future development costs	[4]				(18,400)		(18,400)		(11,900)
Future income taxes	[4]				(24,311)		(32,423)		(31,748)
Future net cash flows	[4]				185,014		167,287		160,948
Discount to present value at 10% annual rate	[4]				(36,194)		(35,161)		(33,483)
Standardized measure of discounted future net cash flows relating to proved oil and gas reserves	[4]	148,820	132,126	127,465	$ 148,820		$ 132,126		$ 127,465
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Balance at Beginning of Period	[4]	132,126	127,465	238,298
Sales and transfers of oil and gas produced, net of production costs	[4]	(45,355)	(19,919)	(52,399)
Net changes in prices and production costs	[4]	46,916	27,572	21,610
Extensions, discoveries, additions and improved recovery, net of related costs	[4]	0	16,287	12,287
Development costs incurred	[4]	0	5,820	12,600
Revisions of estimated development cost	[4]	0	(11,108)	(3,814)
Revisions of previous quantity estimates	[4]	(1,764)	1,198	31,750
Accretion of discount	[4]	15,307	14,909	24,839
Net change in income taxes	[4]	3,022	682	(11,529)
Purchases of reserves in place	[4]	0	0	0
Sales of reserves in place	[4]	0	0	(82,058)
Changes in timing and other	[4]	(1,432)	(30,780)	(64,119)
Balance at End of Period	[4]	$ 148,820	$ 132,126	$ 127,465
Other International (1) | Crude Oil
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Per unit price used to calculate future cash inflows					41.87		57.22		61.66
Other International (1) | Natural Gas
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Per unit price used to calculate future cash inflows					5.65		5.01		4.88

[1] Estimated crude oil prices used to calculate 2020 future cash inflows for the United States, Trinidad and Other International were $37.19, $26.75, and $41.87, respectively. Estimated NGL price used to calculate 2020 future cash inflows for the United States was $12.47. Estimated natural gas prices used to calculate 2020 future cash inflows for the United States, Trinidad and Other International were $1.45, $3.28, and $5.65, respectively.

[2] Estimated crude oil prices used to calculate 2019 future cash inflows for the United States, Trinidad and Other International were $57.51, $46.77 and $57.22, respectively. Estimated NGL price used to calculate 2019 future cash inflows for the United States was $16.91. Estimated natural gas prices used to calculate 2019 future cash inflows for the United States, Trinidad and Other International were $2.07, $2.90 and $5.01, respectively.

[3] Estimated crude oil prices used to calculate 2018 future cash inflows for the United States, Trinidad and Other International were $68.54, $55.66 and $61.66, respectively. Estimated NGL price used to calculate 2018 future cash inflows for the United States was $27.83. Estimated natural gas prices used to calculate 2018 future cash inflows for the United States, Trinidad and Other International were $2.50, $3.06 and $4.88, respectively.

[4] Other International includes EOG's United Kingdom, China and Canada operations. The United Kingdom operations were sold in the fourth quarter of 2018.