Properties, Plant and Equipment (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Property Plant and Equipment (Textual) [Abstract]
Minimum percentage accountability of the U.S., Nigeria and Australia, of net Properties, Plant and Equipment	0.10
Net Properties, Plant and Equipment of Nigeria	$ 15,601	$ 13,896	$ 12,463
Net Properties, Plant and Equipment of Australia	12,423
Dry Hole Expense Related To Prior Year Net	45	82	84
Accretion expense	$ 628	$ 513	$ 463