Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Effective income tax rate	15.90%		0.10%
Income taxes	$ 114		$ 0
Income from continuing operations before income taxes	$ 718		$ 265
Provisional income tax expense		$ 345