Description of Business, Accounting Policies, and Supplemental Disclosures - Other Income (Expense), Net (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Feb. 02, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Valuations and adjustments of equity securities		$ 833	$ 231	$ 145
Derivative [Line Items]
Foreign currency gains (losses)		35	(20)	(206)
Subsequent Event
Subsequent Event [Line Items]
Upward adjustments relating to equity investments in private companies	$ 1,500
Gains on equity and equity warrant investments in public companies	$ 1,500
Equity Warrant
Derivative [Line Items]
Derivative gains (losses)		$ 1,500	$ 11	$ (131)