Debt (Summary of Long-Term Debt) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Summary of long term debt
Senior Notes	$ 5,800
Debt at face value	5,961	6,973
Capitalized leases	(199)	(6)
Net unamortized premiums and discounts	(5)	(5)
Total debt	6,155	6,974
Short-term debt	(24)	(13)
Long-term debt	6,131	6,961
1.95% Senior Notes Due 2015 [Member]
Summary of long term debt
Senior Notes	800	800
Stated interest rate of debt	1.95%
2.95% Senior Notes Due 2017 [Member]
Summary of long term debt
Senior Notes	1,500	1,500
Stated interest rate of debt	2.95%
4.30% Senior Notes Due 2022 [Member]
Summary of long term debt
Senior Notes	2,000	2,000
Stated interest rate of debt	4.30%
5.875% Senior Notes Due 2042 [Member]
Summary of long term debt
Senior Notes	1,500	1,500
Stated interest rate of debt	5.875%
Industrial Development Bonds due 2018 through 2021 at 0.05% - 0.07% at year-end 2013 and 0.09% - 0.23% at year-end 2012 [Member]
Summary of long term debt
Debt	50	50
Stated percentage of debt minimum	0.05%	0.09%
Stated percentage of debt maximum	0.07%	0.23%
Term loan due 2014 through 2015 at 1.465% at December 31, 2012 [Member]
Summary of long term debt
Debt	0	1,000
Stated interest rate of debt		1.465%
Note payable to Merey Sweeny, L.P. due 2020 at 7% (related party) [Member]
Summary of long term debt
Notes Payable to Merey Sweeny, L.P. (related party)	110	122
Stated interest rate of debt	7.00%
Other [Member]
Summary of long term debt
Debt	$ 1	$ 1