Acquisition, Dispositions, Goodwill and Other Intangible Assets (Goodwill) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019 USD ($)
Goodwill [Line Items]
Goodwill - Beginning Balance	$ 48,112
Goodwill Resulting from Business Combinations	410
Goodwill - Foreign Currency Translation and Other	(481)
Goodwill - Ending Balance	48,041
Otis [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	1,688
Goodwill Resulting from Business Combinations	14
Goodwill - Foreign Currency Translation and Other	(80)
Goodwill - Ending Balance	1,622
Carrier [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	9,835
Goodwill Resulting from Business Combinations	1
Goodwill - Foreign Currency Translation and Other	(136)
Goodwill - Ending Balance	9,700
Pratt & Whitney [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	1,567
Goodwill Resulting from Business Combinations	1
Goodwill - Foreign Currency Translation and Other	(4)
Goodwill - Ending Balance	1,564
Collins Aerospace Systems [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	35,001
Goodwill Resulting from Business Combinations	394
Goodwill - Foreign Currency Translation and Other	(261)
Goodwill - Ending Balance	35,134
Total Segments [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	48,091
Goodwill Resulting from Business Combinations	410
Goodwill - Foreign Currency Translation and Other	(481)
Goodwill - Ending Balance	48,020
Eliminations and other [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	21
Goodwill Resulting from Business Combinations	0
Goodwill - Foreign Currency Translation and Other	0
Goodwill - Ending Balance	21
Customer relationships and other [Member]
Goodwill [Line Items]
Goodwill, Purchase Accounting Adjustments	100
Property, Plant and Equipment [Member]
Goodwill [Line Items]
Goodwill, Purchase Accounting Adjustments	$ 130