Income Taxes Components of current and long-term deferred income taxes (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred Tax Assets and Liabilities [Line Items]
Deferred tax liabilities included in other current liabilities		$ 49
Current assets and liabilities [Member]
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals [Abstract]
Employee benefits	116	92
Depreciation and amortization	(2)	(3)
Other accruals and adjustments	497	495
Deferred Tax Assets, Net, Classification [Abstract]
Other items	0	0
United States federal income tax loss carryforwards	0	0
United States federal income tax credit carryforward	0	0
United States state and local tax loss carryforwards and tax credit carryforwards	0	0
Other foreign tax loss carryforward	0	0
Other foreign income tax credit carryforwards	0	0
Valuation allowance for income tax loss and income tax credit carryforwards	0	(61)
Other valuation allowance	(34)	(7)
Total deferred income taxes	577	516
Long-term assets and liabilities [Member]
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals [Abstract]
Employee benefits	657	857
Depreciation and amortization	(2,294)	(2,793)
Other accruals and adjustments	368	297
Deferred Tax Assets, Net, Classification [Abstract]
Other items	0	145
United States federal income tax loss carryforwards	0	6
United States federal income tax credit carryforward	161	156
United States state and local tax loss carryforwards and tax credit carryforwards	73	71
Other foreign tax loss carryforward	1,708	1,591
Other foreign income tax credit carryforwards	63	67
Valuation allowance for income tax loss and income tax credit carryforwards	(1,738)	(1,521)
Other valuation allowance	(71)	(71)
Total deferred income taxes	$ (1,073)	$ (1,195)