Segment Information (Details) (USD $)
In Millions
3 Months Ended9 Months Ended
Sep. 30, 2011
Sep. 30, 2010
Sep. 30, 2011
Sep. 30, 2010
Dec. 31, 2010
Segment Information [Line Items]     
Oil and gas revenues$ 628$ 449$ 1,794$ 1,355 
Operating expenses:     
Lease operating11586333237 
Production and other taxes952124577 
Depreciation, depletion and amortization189156528463 
General and administrative5140132117 
Total income tax provision (benefit)15593273293 
Other00010 
Total operating expenses4503031,238904 
Income (Loss) from operations178146556451 
Interest expenses, net of interest income, capitalized interest and other(16)(23)(61)(71) 
Commodity derivative income262131249414 
Income before income taxes424254744794 
Additions to long-lived assets6913902,1141,412 
Total assets8,9037,2268,9037,2267,494
Domestic [Member]
     
Segment Information [Line Items]     
Oil and gas revenues4443571,3131,055 
Operating expenses:     
Lease operating9368260195 
Production and other taxes1925633 
Depreciation, depletion and amortization154128440371 
General and administrative4939128113 
Total income tax provision (benefit)4844159124 
Other00010 
Additions to long-lived assets5973641,8581,280 
Total assets7,8796,4207,8796,420 
Net Income (Loss) From Oil And Gas Properties8176270209 
Malaysia [Member]
     
Segment Information [Line Items]     
Oil and gas revenues15980416259 
Operating expenses:     
Lease operating21176939 
Production and other taxes711717338 
Depreciation, depletion and amortization29247378 
General and administrative1133 
Total income tax provision (benefit)1483739 
Other0000 
Additions to long-lived assets811820899 
Total assets789604789604 
Net Income (Loss) From Oil And Gas Properties23136162 
China [Member]
     
Segment Information [Line Items]     
Oil and gas revenues25126541 
Operating expenses:     
Lease operating1143 
Production and other taxes52166 
Depreciation, depletion and amortization641511 
General and administrative1011 
Total income tax provision (benefit)3276 
Other0000 
Additions to long-lived assets1384833 
Total assets235202235202 
Net Income (Loss) From Oil And Gas Properties932214 
Other International [Member]
     
Segment Information [Line Items]     
Oil and gas revenues0000 
Operating expenses:     
Lease operating0000 
Production and other taxes0000 
Depreciation, depletion and amortization0003 
General and administrative0000 
Total income tax provision (benefit)000(1) 
Other0000 
Additions to long-lived assets0000 
Total assets0000 
Net Income (Loss) From Oil And Gas Properties$ 0$ 0$ 0$ (2)