Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Line Items]
Income tax (benefit) expense		$ 513	$ (77)	$ 232
Net discrete tax adjustments		294	(458)	(18)
Provisional tax expense, Tax Cuts and Jobs Act of 2017		299
Discrete adjustments, other		5
Provisional tax expense, Tax Cuts and Jobs Act of 2017, revaluing deferred tax assets		384
Provisional tax expense, Tax Cuts and Jobs Act of 2017, reversal of foreign earnings reserves		162	0	0
Provisional tax expense, Tax Cuts and Jobs Act of 2017, one-time transition tax		77
Income tax benefit resulting from election change			163
Tax benefit from the conclusion of non-U.S. tax claims				9
Loss on deconsolidation of Venezuelan subsidiary	$ 646	0	0	646
Tax benefit from research and development tax credit				10
Operating loss carryforwards, foreign		605
Valuation allowance		318	326
Federal tax assets for net operating loss and tax credit carryforwards		816
State tax assets for net operating loss and tax credit carryforwards		94
Foreign tax credits subject to expiration		749
Tax credits from research and development		67
Unrecognized tax benefits	$ 54	52	63	54	$ 81
Favorable tax expense impact of unrecognized tax benefits, if recognized		37
Accrued interest		2
Unsettled unrecognized tax benefits that would require cash		5
Undistributed earnings on foreign subsidiaries, reserve		19	181
Undistributed foreign subsidiaries earnings		1,000
Amount of unrecognized deferred tax liability, undistributed earnings of foreign subsidiaries		74
Income tax cash payments, net		144	153	113
Foreign Tax Authority
Income Taxes [Line Items]
Net establishment (release) of valuation allowances		1	(354)	4
Operating loss carryforwards, foreign		53
Valuation allowance		230
Foreign Tax Authority | Deferred Tax Assets of Certain Subsidiaries in England, France, Luxembourg and New Zealand
Income Taxes [Line Items]
Net establishment (release) of valuation allowances			(331)
Domestic Tax Authority
Income Taxes [Line Items]
Net establishment (release) of valuation allowances		5	39	(8)
Tax benefit from loss on deconsolidation of subsidiary				$ 69
Domestic Tax Authority | Deferred Tax Assets From Receivables of Deconsolidated Venezuelan Operations
Income Taxes [Line Items]
Net establishment (release) of valuation allowances			39
Domestic Tax Authority | Deferred Tax Assets Related to Brazil
Income Taxes [Line Items]
Net establishment (release) of valuation allowances			$ (7)
Domestic and State and Local Authority
Income Taxes [Line Items]
Valuation allowance		$ 88