Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011
Financial Liabilities:
Proved oil and gas properties and other property, plant and equipment written down to fair value during the period - carrying amount	$ 120
Proved Oil and Gas Properties and Other Property, Plant and Equipment Written Down During the Period - Fair value at End of Period	45
Impairment Charge for Proved Oil and Gas Properties and Other Property, Plant and Equipment, in which EOG utilized an accepted offer from a third-party buyer	58
Impairment Charge For Proved Oil And Gas Properties And Other Property, Plant And Equipment	75
Fair Value of Debt	5,644	5,657
Total Long-Term Debt	5,040	5,040
Fair Value, Inputs, Level 2 [Member]
Financial Assets:
Financial Assets: Crude Oil and Natural Gas Derivative Contracts		110
Financial Assets: Crude Oil and Natural Gas Options/Swaptions		376
Financial Assets: Natural Gas Derivative Contracts	80
Financial Assets: Natural Gas Options/Swaptions	432
Financial Liabilities:
Financial Liabilities: Foreign Currency Rate Swap	54	52
Financial Liabilities: Interest Rate Swap	4	3
Financial Liabiliites: Crude Oil Derivative Contracts	4
Financial Liabilities: Crude Oil Options/Swaptions	$ 22