Income Taxes - Changes in the Valuation Allowance for Deferred Tax Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Changes In The Valuation Allowance For Deferred Tax Assets, Valuation Allowance [Roll Forward]
Beginning balance	$ 2,312	$ 1,906	$ 632
Additions charged to income tax expense and other accounts	635	430	1,403
Deductions from reserves	40	24	129
Ending balance	$ 2,907	$ 2,312	$ 1,906