Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Effective Tax Rate
Income from continuing operations before income taxes	$ 380	$ 295	$ 666	$ 572
Income tax expense from continuing operations	$ 6	$ 8	$ 9	$ 19
Effective income tax rate	1.60%	2.70%	1.40%	3.30%
Uncertain Tax Benefits
Non-current tax liability for uncertain tax benefits	$ 29		$ 29
Uncertain tax benefits, penalties and interest accrued	$ 5		$ 5