Fair Value Measurements and Disclosures (Details 3) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011
Carrying (Reported) Amount, Fair Value Disclosure
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long Term Debt Net Of Unamortized Discount	$ 4,121	[1]	$ 4,114	[1]
Estimate of Fair Value, Fair Value Disclosure
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long Term Debt Net Of Unamortized Discount	$ 4,712	[1]	$ 4,733	[1]

[1] Excludes Aseng FPSO lease obligation. No floating rate debt was outstanding at June 30, 2012 or December 31, 2011. See Note 5. Debt.