Risk Management Activities (Details) (USD $)	3 Months Ended		9 Months Ended															9 Months Ended		12 Months Ended		9 Months Ended	6 Months Ended		9 Months Ended			6 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Sep. 30, 2012 Crude Oil and Natural Gas Derivative Contracts [Member] Liabilities From Price Risk Management Activities [Member]	Dec. 31, 2011 Crude Oil and Natural Gas Derivative Contracts [Member] Liabilities From Price Risk Management Activities [Member]	Sep. 30, 2012 Crude Oil and Natural Gas Derivative Contracts [Member] Assets From Price Risk Management Activities [Member]	Dec. 31, 2011 Crude Oil and Natural Gas Derivative Contracts [Member] Assets From Price Risk Management Activities [Member]	Sep. 30, 2012 Crude Oil and Natural Gas Derivative Contracts [Member] Other Assets [Member]	Dec. 31, 2011 Crude Oil and Natural Gas Derivative Contracts [Member] Other Assets [Member]	Sep. 30, 2012 Crude Oil and Natural Gas Derivative Contracts [Member] Other Liabilities [Member]	Dec. 31, 2011 Crude Oil and Natural Gas Derivative Contracts [Member] Other Liabilities [Member]	Sep. 30, 2012 Interest Rate Swap [Member] Other Liabilities [Member]	Dec. 31, 2011 Interest Rate Swap [Member] Other Liabilities [Member]	Sep. 30, 2012 Foreign Currency Swap [Member] Other Liabilities [Member]	Dec. 31, 2011 Foreign Currency Swap [Member] Other Liabilities [Member]	Sep. 30, 2012 Crude Oil Derivative Contracts January - February [Member]	Sep. 30, 2012 Natural Gas Derivative Contracts January - October [Member]	Dec. 31, 2013 Natural Gas Derivative Contracts Year Two January - December [Member]	Dec. 31, 2014 Natural Gas Derivative Contracts Year Three January - December [Member]	Sep. 30, 2012 Natural Gas Derivative Contracts - November - December [Member]	Jun. 30, 2014 Crude Oil Derivative Contracts January - June Year Three [Member]	Jun. 30, 2013 Crude Oil Derivative Contracts January - June Year Two [Member]	Sep. 30, 2012 Crude Oil Derivative Contracts March - June [Member]	Sep. 30, 2012 Crude Oil Derivative Contracts July - August [Member]	Sep. 30, 2012 Crude Oil Derivative Contracts September [Member]	Dec. 31, 2013 Crude Oil Derivative Contracts July - December Year Two [Member]	Sep. 30, 2012 Crude Oil Derivative Contracts October - December [Member]
Derivative [Line Items]
Volume (MMBtu)																			525,000	150,000		525,000
Volume (Bbld)																		34,000						98,000	52,000	50,000	32,000	54,000	42,000
Volumes (MMBtud) - Derivative Option Contracts																				150,000	150,000	425,000
Average Price ($/MMBtu) - Derivative Option Contracts																				4.79	4.79	5.44
Derivative Weighted Average Price Crude Oil ($/Bbl)																		104.95						99.39	105.80	106.90	106.61	99.38	105.19
Derivative Weighted Average Price Natural Gas ($/MMBtu)																			5.44	4.79		5.44
Volumes (Bbld) - Derivative Option Contracts																							15,000	25,000				59,000
Average Price ($/Bbl) - Derivative Option Contracts																							103.54	106.27				100.45
Proceeds from financial derivative contracts settled during the period			$ 36,600,000
Derivatives, Fair Value [Line Items]
Derivatives Assets, Current	248,698,000		248,698,000		450,730,000			238,000,000	451,000,000
Other Assets										14,000,000	35,000,000
Derivative Liabilities, Current						1,000,000	0
Other Liabilities												6,000,000	0	4,000,000	3,000,000	57,000,000	52,000,000
Foreign Currency Exchange Rate Derivative [Abstract]
Debt Instrument Issued by EOG's Canadian Subsidiary	150,000,000		150,000,000
After-Tax Net Impact Other Comprehensive Income Increase (Decrease) From The Foreign Currency Swap	1,100,000	500,000	1,700,000	300,000
Interest Rate Cash Flow Hedges [Abstract]
Interest Rate Swap, Notional Amount	350,000,000		350,000,000
After-Tax Net Impact From Interest Rate Swap	(200,000)	(1,600,000)	(400,000)	(4,200,000)
Derivative Collateral [Abstract]
Collateral Held on Derivative					$ 67,000,000