Lease Commitments (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Leased Assets [Line Items]
Non-cancelable term of operating and capital leases (in years)	1 year
Schedule of capitalized leased assets
Upstream	$ 445	$ 433
Downstream	316	316
All Other	0	0
Total	761	749
Less: Accumulated amortization	523	479
Net capitalized leased assets	238	270
Rental expenses incurred for operating leases
Minimum rentals	1,049	973	892
Contingent rentals	1	7	11
Total	1,050	980	903
Less: Sublease rental income	25	32	39
Net rental expense	1,025	948	864
Estimated future minimum lease payments (net of noncancelable sublease rentals) under operating and capital leases
Operating Leases, 2014	798
Capital Leases, 2014	45
Operating Leases, 2015	733
Capital Leases, 2015	32
Operating Leases, 2016	594
Capital Leases, 2016	20
Operating Leases, 2017	472
Capital Leases, 2017	17
Operating Leases, 2018	306
Capital Leases, 2018	17
Operating Leases, Thereafter	806
Capital Leases, Thereafter	46
Operating Leases, Total	3,709
Capital Leases, Total	177
Less: Amounts representing interest and executory costs	(37)
Net present values	140
Less: Capital lease obligations included in short-term debt	(43)
Long-term capital lease obligations	$ 97	$ 99
Maximum [Member]
Operating Leased Assets [Line Items]
Contingent rentals, renewal option term (in years)	25 years