Income Taxes (Schedule of Provision for (Benefit) from Income Taxes for Income from Continuing Operations) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ (38)	$ 1
State	(5)	(9)	$ 5
Total, Current	(43)	(8)	5
Deferred:
Federal	179	50	(485)
State	24	(53)	31
Total, Deferred	203	(3)	(454)
Total provision for (benefit from) income taxes for loss from continuing operations	$ 160	$ (11)	$ (449)