Income Taxes (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Valuation Allowance [Line Items]
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount		$ 20
Effective income tax rate reconciliation [Abstract]
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense		(47)	$ (117)
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Tax Credit Carryforward, Valuation Allowance		111	189
Effective income tax rate		297
Details of income tax provision (benefit) [Abstract]
Effective income tax rate		297
U.S. and foreign income before income taxes [Abstract]
Income from Continuing Operations Before Income Taxes		1,839	2,274	$ 1,345
U.S. state [Member]
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Tax Credit Carryforward, Valuation Allowance		100
Internal Revenue Service (IRS) [Member]
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Tax Credit Carryforward, Valuation Allowance		300
Foreign Tax Credit [Domain]
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Tax Credit Carryforward, Valuation Allowance		100
Current Year Operations
Changes in valuation allowance [Roll Forward]
Valuation Allowance, Change in Amount		(78)		(14)
Changes in Judgement
Changes in valuation allowance [Roll Forward]
Valuation Allowance, Change in Amount				$ (17)
Continuing Operations [Member]
Valuation Allowance [Line Items]
Deferred Tax Assets, Net of Valuation Allowance, Current		$ 195	$ 139
Effective income tax rate reconciliation [Abstract]
U.S. federal statutory rate (in hundredths)		21.00%	35.00%	35.00%
State income tax, net of federal tax benefit (in hundredths)		1.00%	0.50%	1.10%
Statutory rate differential attributable to foreign operations (in hundredths)		(12.30%)	(9.30%)	(10.50%)
Adjustments to reserves and prior years (in hundredths)		2.80%	0.50%	(0.80%)
Change in valuation allowance (in hundredths)		8.50%	1.50%	(0.20%)
Other, net (in hundredths)		(0.40%)	(1.10%)	(0.30%)
Effective income tax rate (in hundredths)		16.20%	41.10%	24.30%
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	[1]		$ (22)	$ (26)
Effective Income Tax Rate Reconciliation Share Based Compensation		(2.50%)	(5.10%)	0.00%
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Change in valuation allowance		$ (156)	$ (34)	$ (3)
Effective income tax rate		297	934	327
Details of income tax provision (benefit) [Abstract]
Current: Federal		102	(2)	126
Current: Foreign		181	290	160
Current: State		25	12	13
Total current income tax provision (benefit)		308	300	299
Deferred: Federal		(24)	603	19
Deferred: Foreign		5	19	3
Deferred: State		8	12	6
Total deferred income tax provision (benefit)		(11)	634	28
Effective income tax rate		297	934	327
U.S. and foreign income before income taxes [Abstract]
U.S.		726	662	366
Foreign		1,113	1,612	979
Income from Continuing Operations Before Income Taxes		1,839	2,274	$ 1,345
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount		$ 35	$ 434
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent		(1.90%)	19.10%	0.00%
Tax Year 2017 [Member]
Effective income tax rate reconciliation [Abstract]
U.S. federal statutory rate (in hundredths)			35.00%
Tax Year 2018 [Domain]
Effective income tax rate reconciliation [Abstract]
U.S. federal statutory rate (in hundredths)		21.00%	21.00%
U.S. and foreign income before income taxes [Abstract]
Limit on deductibility of interest expense			30.00%
Tax Year 2018 [Member] | Continuing Operations [Member]
U.S. and foreign income before income taxes [Abstract]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount		$ 399
Repatriation Tax Liability [Member]
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Effective income tax rate		241
Details of income tax provision (benefit) [Abstract]
Effective income tax rate		241
Remeasurement of Deferreds [Domain]
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Effective income tax rate		47
Details of income tax provision (benefit) [Abstract]
Effective income tax rate		$ 47
Prior Year Divestiture [Member] | Continuing Operations [Member]
Effective income tax rate reconciliation [Abstract]
Adjustments to reserves and prior years (in hundredths)		1900000000.00%

[1] Deferred tax benefit recognized does not reflect the impact of the Tax Act. See Note 17.