Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Federal statutory income tax rate			35.00%	35.00%	35.00%
Benefit of Tax Cuts and Jobs Act of 2017	$ 689		$ 689
Income before income taxes, foreign			48	$ 29	$ 70
Undistributed earnings of foreign subsidiaries amount	617		617
Valuation allowance	39		39	$ 9
Operating loss carryforwards utilized during period			289
Federal Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	587		587
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	773		773
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	$ 26		$ 26
Scenario, Forecast
Operating Loss Carryforwards [Line Items]
Federal statutory income tax rate		21.00%