Financial Instruments - Investments - Unrealized Gains and Losses Related to Equity Securities (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Financial Instruments [Abstract]
Net (gains)/losses recognized during the period on investments in equity securities	[1],[2]	$ (1,344)	$ (540)	$ (454)
Less: Net (gains)/losses recognized during the period on equity securities sold during the period		(80)	(24)	(25)
Net unrealized (gains)/losses during the reporting period on equity securities still held at the reporting date	[3]	$ (1,264)	$ (515)	$ (429)

[1] Reported in Other (income)/deductions––net. See Note 4.

[2] (b)2021 gains include, among other things, unrealized gains of $1.6 billion related to investments in BioNTech and Cerevel. 2020 gains included, among other things, unrealized gains of $405 million related to investments in BioNTech and SpringWorks Therapeutics, Inc. (SpringWorks). 2019 gains included, among other things, unrealized gains of $295 million related to investments in Cortexyme, Inc. and SpringWorks.

[3] Included in net unrealized gains are observable price changes on equity securities without readily determinable fair values. As of December 31, 2021, there were cumulative impairments and downward adjustments of $97 million and upward adjustments of $156 million. Impairments, downward and upward adjustments were not significant in 2021, 2020 and 2019