Acquisitions, Dispositions, Goodwill and Intangible Assets (Intangible Assets) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Amount		$ 38,841	$ 38,757
Accumulated Amortization		(7,551)	(6,932)
Unamortized: Trademarks and Other		8,709	8,714
Total Intangible Assets Gross Excluding Goodwill		47,550	47,471
Collins Aerospace Systems [Member]
Finite-Lived Intangible Assets [Line Items]
Impairment of Intangible Assets (Excluding Goodwill)	$ 40
Patents and trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount		48	48
Accumulated Amortization		(36)	(35)
Collaboration assets
Finite-Lived Intangible Assets [Line Items]
Gross Amount		5,047	5,021
Accumulated Amortization		(1,042)	(1,024)
Exclusivity assets
Finite-Lived Intangible Assets [Line Items]
Gross Amount		2,581	2,541
Accumulated Amortization		(305)	(295)
Developed technology and other
Finite-Lived Intangible Assets [Line Items]
Gross Amount		928	906
Accumulated Amortization		(364)	(316)
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Amount		30,237	30,241
Accumulated Amortization		$ (5,804)	$ (5,262)

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

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Amount before accumulated amortization of intangible assets, excluding goodwill.

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