Income Taxes Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income tax expense from continuing operations	$ (90)	$ 113	$ 21	$ 189
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 200