Commitments and Contingencies, Operating Leases (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009
Operating lease term	17
Rental expense for operating leases	$ 398		$ 347	$ 374
Operating Leases, Future Minimum Payments Due [Abstract]
2012	213
2013	162
2014	125
2015	112
2016	103
Thereafter	442
Total minimum rental payments	1,157
Ship Charters (a) [Member]
Number of ships	7
Time charter terms range lower limit	3
Time charter terms range upper limit	7
Operating Leases, Future Minimum Payments Due [Abstract]
2012	100	[1]
2013	50	[1]
2014	18	[1]
2015	11	[1]
2016	10	[1]
Thereafter	0	[1]
Total minimum rental payments	189	[1]
Minimum annual lease payment for tugs and barges lower limit	10
Minimum annual lease payment for tugs and barges upper limit	33
U.S.-flag ships [Member]
Number of ships	4
Operating Leases, Future Minimum Payments Due [Abstract]
Time charter expiration date range start	Jan. 01, 2012
Time charter expiration date range end	Jan. 01, 2013
Foreign-flag ships [Member]
Number of ships	3
Operating Leases, Future Minimum Payments Due [Abstract]
Time charter expiration date range start	Jan. 01, 2012
Time charter expiration date range end	Jan. 01, 2013
Tugs and barges [Member]
Operating Leases, Future Minimum Payments Due [Abstract]
Time charter expiration date range start	Jan. 01, 2012
Time charter expiration date range end	Jan. 01, 2016
Other [Member]
Operating Leases, Future Minimum Payments Due [Abstract]
2012	113
2013	112
2014	107
2015	101
2016	93
Thereafter	442
Total minimum rental payments	$ 968
Retail stations [Member]
Operating lease term	41
Storage tanks [Member]
Lease expiration date	2017

[1] Includes minimum annual lease payments for tugs and barges, which range between $10 million and $33 million over the next five years.