Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Income Taxes [Abstract]
Unrecognized tax benefits that would impact effective tax rate if recognized	$ 13		$ 13		$ 14
Unrecognized tax benefits, reasonably possible decrease within the next 12 months	$ 2		$ 2
Effective tax rate on income from continuing operations (as a percent)	(231.30%)	34.80%	61.80%	17.40%