Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
Income before income taxes, foreign	$ 71	$ 48	$ 29
Tax Cuts And Jobs Act Of 2017 transition tax	62
Undistributed earnings of foreign subsidiaries amount	651
Valuation allowance	46	39
Operating loss carryforwards utilized during period	386
Federal Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	1,468
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	1,180
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	29
Tax credit carryforward	$ 32	$ 26