Income Taxes Income Tax Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Operating Loss Carryforwards [Line Items]
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Provisional Income Tax Expense		$ 7		$ 55
Tax Cuts and Jobs Act of 2017, Indirect Impact on Inventory, Income Tax Expense				$ 16
Tax charge related to U.S. state blended tax rate changes associated with the Business Separations	$ 114		$ 146
Tax charge related to application of the Act's foreign tax provisions	96		96
Tax benefit related to an internal legal entity restructuring associated with the Intended Business Separations			102
Other Tax Benefit	$ 21		$ 21