Income Taxes (Reconciliation of Provision for Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Expected provision (benefit) at federal statutory rate	$ 400	$ (5)	$ (568)
Increase (decrease) resulting from:
State income taxes, net of federal income tax effect	39	0	(55)
Change in valuation allowance	(392)	2	1,034
Other	4	3	(4)
Provision for Income Taxes	$ 51	$ 0	$ 407