Income Taxes (Reconciliation of Deferred Tax Asset Valuation Allowance) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Taxes [Abstract]
Beginning balance	$ 9,965	$ 10,214	$ 3,040
Deferred Tax Asset, Valuation Allowance, Charged To Expense	45	(460)	225
Deferred Tax Assets, Valuation Allowance, Other	(1,578)	(709)	7,399
Ending balance	$ 8,342	$ 9,965	$ 10,214