Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 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	$ 178
Proved Oil and Gas Properties and Other Property, Plant and Equipment Written Down During the Period - Fair value at End of Period	82
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	60
Impairment Charge For Proved Oil And Gas Properties And Other Property, Plant And Equipment	96
Fair Value of Debt	5,735	5,657
Total Long-Term Debt	5,040	5,040
Fair Value, Inputs, Level 1 [Member]
Financial Assets:
Financial Assets: Crude Oil Derivative Contracts	0	0
Financial Assets: Crude Oil Options/Swaptions	0	0
Financial Assets: Natural Gas Derivative Contracts	0	0
Financial Assets: Natural Gas Options/Swaptions	0	0
Financial Liabilities:
Financial Liabilities: Foreign Currency Rate Swap	0	0
Financial Liabilities: Interest Rate Swap	0	0
Fair Value, Inputs, Level 2 [Member]
Financial Assets:
Financial Assets: Crude Oil Derivative Contracts	54	29
Financial Assets: Crude Oil Options/Swaptions	86	4
Financial Assets: Natural Gas Derivative Contracts	45	81
Financial Assets: Natural Gas Options/Swaptions	279	372
Financial Liabilities:
Financial Liabilities: Foreign Currency Rate Swap	51	52
Financial Liabilities: Interest Rate Swap	4	3
Fair Value, Inputs, Level 3 [Member]
Financial Assets:
Financial Assets: Crude Oil Derivative Contracts	0	0
Financial Assets: Crude Oil Options/Swaptions	0	0
Financial Assets: Natural Gas Derivative Contracts	0	0
Financial Assets: Natural Gas Options/Swaptions	0	0
Financial Liabilities:
Financial Liabilities: Foreign Currency Rate Swap	0	0
Financial Liabilities: Interest Rate Swap	$ 0	$ 0