Income Taxes Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Tax Contingency [Line Items]
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Provisional Income Tax Expense		$ 48
Tax Cuts and Jobs Act of 2017, Indirect Impact on Inventory, Income Tax Expense		$ 16
Repatriation Accrual [Member]
Income Tax Contingency [Line Items]
Other Tax Expense (Benefit)	$ 13
Internal Entity Restructuring [Member]
Income Tax Contingency [Line Items]
Other Tax Expense (Benefit)	$ (102)