Income Taxes (Schedule of Components of Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current taxes:
State	$ 12	$ 14	$ 10
Total current tax provision	12	14	10
Deferred taxes:
Federal	28	31	(247)
State	(1)	9	6
Total deferred tax provision (benefit)	27	40	(241)
Change in valuation allowance	0	(4)	1
Total tax provision (benefit)	$ 39	$ 50	$ (230)