Goodwill (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Goodwill [Line Items]
Beginning balance, gross			$ 1,937	$ 1,948
Less: accumulated impairment			(1,412)	(1,412)
Goodwill [Roll Forward]
Beginning balance, net	525		536
Dispositions	(26)		(11)
Ending balance, net	499		525
North America Exploration and Production [Member]
Goodwill [Line Items]
Beginning balance, gross			343
Less: accumulated impairment			0
Goodwill [Roll Forward]
Beginning balance, net	343
Dispositions	4	[1]
Ending balance, net	347
International Exploration and Production [Member]
Goodwill [Line Items]
Beginning balance, gross			182
Less: accumulated impairment			0
Goodwill [Roll Forward]
Beginning balance, net	182
Dispositions	(30)
Ending balance, net	152
Exploration and Production Segment [Member]
Goodwill [Line Items]
Beginning balance, gross				536
Less: accumulated impairment				0
Goodwill [Roll Forward]
Beginning balance, net			536
Dispositions			(11)
Ending balance, net			525
Oil Sands Mining Segment [Member]
Goodwill [Line Items]
Beginning balance, gross			1,412	1,412
Less: accumulated impairment			(1,412)	(1,412)
Goodwill [Roll Forward]
Beginning balance, net	0		0
Dispositions	0		0
Ending balance, net	$ 0		$ 0

[1] Goodwill related to our Alaska disposition was less than the estimate classified as held for sale in 2012.