Income Taxes, Income Tax Returns (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Anticipated decrease in unrecognized tax benefits over the next 12 months	$ 27
Reversal of previously accrued income tax expense, including interest and penalties	35	$ 4	$ 25
Accrued potential interest included within current and non-current income taxes payable	15
Accrued potential interest included within current and non-current income taxes payable after income taxes	11
Potential penalties	9	8
Benefit (Expense) Related Items Included in Income Taxes Expenses	2	$ 5
Undistributed earnings of non-U.S. Companies	$ 1,000