v2.4.0.6
Supplemental Information On Oil And Gas Operations (Narrative) (Details) (USD $)
 12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Boe
Reserve Quantities [Line Items]      
Capitalized general and administrative expenses $ 337,000,000 $ 311,000,000 $ 332,000,000
Capitalized interest expenses (72,000,000) (76,000,000) (94,000,000)
Proved undeveloped reserves 782    
Decrease in proved undeveloped reserves 6.00%    
Percentage of total proved reserves 26.00%    
Proved undeveloped reserves, drilling activities 148    
Proved undeveloped reserves, drilling activities, conversion 130    
Proved undeveloped reserves to proved developed reserves, conversion, percentage 16.00%    
Increase in reserves due to adoption of SEC' modernization of oil and gas reporting (MMBoe)     65
Percent increase in reserves due to adoption of SEC's modernization of oil and gas reporting     2.00%
Average price per barrel of oil used to estimate proved oil reserves 67.31    
Average price per Mcf of gas used to estimated proved gas 3.51    
Average price per barrel of natural gas liquids used to estimate proved NGL reserves 39.28    
Future development costs 11,500,000,000    
Future development costs estimated to be spent in 2012 1,600,000,000    
Future development costs estimated to be spent in 2013 1,400,000,000    
Future development costs estimated to be spent in 2014 1,100,000,000    
Future dismantlement, abandonment and rehabilitation costs 2,200,000,000    
Future net revenues discounted 10.00%    
After tax future net revenue discounted 17,800,000,000    
Standardized measure discounted future income taxes 7,100,000,000    
Pre tax future net revenue 24,900,000,000    
Pre tax present value percentage 10.00%    
Barnett Shale [Member]
      
Reserve Quantities [Line Items]      
Proved developed and undeveloped reserves, revisions due to prices   43  
Proved developed and undeveloped reserves, extensions and discoveries 115 87 204
Proved developed and undeveloped reserves, extensions and discoveries related to additions from in fill drilling activities 77 43 203
Jackfish [Member]
      
Reserve Quantities [Line Items]      
Unproved developed and undeveloped reserves, revisions due to prices     331
Proved developed and undeveloped reserves, extensions and discoveries 30 55 118
Proved developed and undeveloped reserves, extensions and discoveries related to additions from in fill drilling activities     118
Proved undeveloped reserves 367 396  
Daily facility capacity 35,000    
Carthage [Member]
      
Reserve Quantities [Line Items]      
Proved developed and undeveloped reserves, extensions and discoveries   14 8
Granite Wash Area [Member]
      
Reserve Quantities [Line Items]      
Proved developed and undeveloped reserves, extensions and discoveries 17    
Cana-Woodford Shale [Member]
      
Reserve Quantities [Line Items]      
Proved developed and undeveloped reserves, extensions and discoveries 162 101 49
Proved developed and undeveloped reserves, extensions and discoveries related to additions from in fill drilling activities 80 47 24
Rocky Mountain [Member]
      
Reserve Quantities [Line Items]      
Proved developed and undeveloped reserves, revisions due to prices   22  
Proved developed and undeveloped reserves, extensions and discoveries 19 15 14
Deepwater Production In The Gulf [Member]
      
Reserve Quantities [Line Items]      
Proved developed and undeveloped reserves, extensions and discoveries     11
Haynesville Shale [Member]
      
Reserve Quantities [Line Items]      
Proved developed and undeveloped reserves, extensions and discoveries     7
Permian Basin [Member]
      
Reserve Quantities [Line Items]      
Proved developed and undeveloped reserves, extensions and discoveries 39 19  
Oil And Gas Properties [Member]
      
Reserve Quantities [Line Items]      
Capitalized interest expenses $ 45,000,000 $ 37,000,000 $ 74,000,000
Total (MMBoe) [Member]
      
Reserve Quantities [Line Items]      
Proved developed and undeveloped reserves, revisions due to prices (21) 72 177
Proved developed and undeveloped reserves, extensions and discoveries 421 354 458
Proved developed and undeveloped reserves, extensions and discoveries related to additions from in fill drilling activities 168 107 371
Total (MMBoe) [Member] | United States [Member]
      
Reserve Quantities [Line Items]      
Proved developed and undeveloped reserves, revisions due to prices     (116)