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Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended						6 Months Ended		12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Accounting Policies [Abstract]
Net pre-tax restructuring costs	$ 427						$ 435
Goodwill impairment	(3,183)				$ 0		(3,183)	$ 0
Allowance for expected credit losses	237						309
Reduction in expected future revenues on commercial aftermarket contracts	179						190
Expected charge due to change in contract estimates	44						44
Contract with Customer, Performance Obligation Satisfied in Previous Period	(218)				(90)		(201)	(115)
Capitalized Contract Cost, Gross	1,808		$ 1,519				1,808		$ 1,519
Revenue, Remaining Performance Obligation, Amount	$ 158,700						$ 158,700
Revenue, Remaining Performance Obligations, to be recognized within 24 months	30.00%						30.00%
Collaborators Interests Existing Programs Low End	1300.00%						1300.00%
Collaborators Interests Existing Programs High End	4900.00%						4900.00%
Partner share individual program maximum	3100.00%						3100.00%
Change in Accounting Estimate [Line Items]
Operating Income (Loss)	$ (3,760)	$ 1,295	956	$ 1,430	1,386	$ 1,142	$ (2,465)	2,528	4,914
Income (loss) from continuing operations attributable to common shareowners	$ (3,844)				$ 1,183		$ (3,406)	$ 1,895
Income (loss) from continuing operations attributable to common shareowners	$ (2.56)				$ 1.37		$ (2.78)	$ 2.20
ASU 2016-13 [Member]
Change in Accounting Estimate [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification							$ 59
Collins Aerospace Systems [Member]
Accounting Policies [Abstract]
Net pre-tax restructuring costs	$ 151						157
Goodwill impairment							(3,183)
Change in Accounting Estimate [Line Items]
Operating Income (Loss)	(317)	$ 1,246	$ 1,009	$ 1,259	$ 1,276	$ 964	929	$ 2,240	$ 4,508
Trade Names [Member] \| Collins Aerospace Systems [Member]
Change in Accounting Estimate [Line Items]
Impairment of Intangible Asset, Tradename	17						$ 57
Minimum [Member]
Change in Accounting Estimate [Line Items]
Operating Cycle							one year
Contracts Accounted for under Percentage of Completion [Member]
Change in Accounting Estimate [Line Items]
Operating Income (Loss)	(151)				(69)		$ (130)	(81)
Income (loss) from continuing operations attributable to common shareowners	$ (119)				$ (55)		$ (103)	$ (64)
Income (loss) from continuing operations attributable to common shareowners	$ (0.08)				$ (0.06)		$ (0.08)	$ (0.07)