Income Taxes (Details 6) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		35.00%	35.00%	35.00%
Impacts related to the 2017 Tax Act		$ 300	$ 0	$ 0
Impacts related to the 2017 Tax Act, Percent		9.80%	0.00%	0.00%
Reduction in Taxes [Member]
Income Tax Contingency [Line Items]
Impacts related to the 2017 Tax Act		$ 280
Impacts related to the 2017 Tax Act, Percent		9.10%
Change in Deferred Tax Assets due to 2017 Tax Act		$ (280)
Change in Other Current Liabilities due to 2017 Tax Act		0
Transition tax on Foreign Earnings [Member]
Income Tax Contingency [Line Items]
Impacts related to the 2017 Tax Act		$ 13
Impacts related to the 2017 Tax Act, Percent		0.40%
Change in Deferred Tax Assets due to 2017 Tax Act		$ (13)
Accelerated Depreciation [Member]
Income Tax Contingency [Line Items]
Impacts related to the 2017 Tax Act		$ 5
Impacts related to the 2017 Tax Act, Percent		0.20%
Change in Deferred Tax Assets due to 2017 Tax Act		$ (80)
Change in Other Current Liabilities due to 2017 Tax Act		(75)
2017 Tax Act, Other [Domain]
Income Tax Contingency [Line Items]
Impacts related to the 2017 Tax Act		$ 2
Impacts related to the 2017 Tax Act, Percent		0.10%
Change in Deferred Tax Assets due to 2017 Tax Act		$ 0
Change in Other Current Liabilities due to 2017 Tax Act		2
2017 Tax Act, Total [Member]
Income Tax Contingency [Line Items]
Change in Deferred Tax Assets due to 2017 Tax Act		(373)
Change in Other Current Liabilities due to 2017 Tax Act		$ (73)
Forecast
Income Tax Contingency [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%