Income Taxes - Textual Information (Details) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2013 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2012 USD ($)
Total Gross Unrecognized Tax Benefits
Deferred Tax Assets, Valuation Allowance		$ 1,210	$ 1,051
Operating Loss Carryforwards, Valuation Allowance		672
Tax Credit Carryforward, Valuation Allowance		425
Other Deferred Tax Assets, Valuation Allowance		113
Components of Deferred Tax Assets and Liabilities [Abstract]
Operating Loss Carryforwards		$ 481
Operating Loss Carryforwards, Expiration Dates		20 years
Deferred tax liability not provided for temporary difference		$ 5,600
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense [Abstract]
Tax liabilities for gross unrecognized tax benefits	$ 282	312	$ 291	$ 267
Interest accrued on income taxes for unrecognized tax benefits		30
Penalties accrued on income taxes for unrecognized tax benefits		21
Unrecognized tax benefits that would impact effective tax rate		289
Deferred Tax Assets, Tax Credit Carryforwards [Abstract]
Deferred tax asset that we did not prevail on all uncertain tax position		23
Uncertain tax positions tax liabilities net of assets		80
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount related to tax assets		13
Unrecognized tax benefits included in noncurrent portion of income tax liabilities		$ 219
Number of countries in which entity operates		80
Income tax benefit, Amount related to Reorganization	(18)
Deferred Tax Liability Not Recognized, Amount of Unrecognized Deferred Tax Liability, Undistributed Earnings of Foreign Subsidiaries	360
Foreign Tax Authority [Member]
Components of Deferred Tax Assets and Liabilities [Abstract]
Net increase in valuation allowance	$ 342
Indefinite Foreign Tax [Member]
Components of Deferred Tax Assets and Liabilities [Abstract]
Deferred Tax Assets, Tax Credit Carryforwards, Foreign		$ 126
Definite Foreign Tax [Member]
Components of Deferred Tax Assets and Liabilities [Abstract]
Deferred Tax Assets, Tax Credit Carryforwards, Foreign		310
Other Tax [Member]
Components of Deferred Tax Assets and Liabilities [Abstract]
Deferred Tax Assets, Tax Credit Carryforwards, Other		$ 22