Income Taxes (Components Of Income (Loss) Before Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Domestic	$ 1,087	$ 917	$ 476
Foreign	247	164	82
Income before income taxes	$ 1,334	$ 1,081	$ 558