Income Taxes (Reconciliation of Provision for Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Expected provision (benefit) at federal statutory rate	$ (5)	$ (568)	$ 101
Increase (decrease) resulting from:
State income taxes, net of federal income tax effect	0	(55)	11
Change in valuation allowance	2	1,034	(522)
Other	3	(4)	(1)
Provision (Benefit) for Income Taxes	$ 0	$ 407	$ (411)

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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