Acquisition, Dispositions, Goodwill and Other Intangible Assets (Goodwill) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Goodwill [Line Items]
Goodwill - Beginning Balance	$ 48,112
Goodwill Resulting from Business Combinations	93
Goodwill - Foreign Currency Translation and Other	187
Goodwill - Ending Balance	48,392
Otis [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	1,688
Goodwill Resulting from Business Combinations	7
Goodwill - Foreign Currency Translation and Other	(11)
Goodwill - Ending Balance	1,684
Carrier [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	9,835
Goodwill Resulting from Business Combinations	1
Goodwill - Foreign Currency Translation and Other	69
Goodwill - Ending Balance	9,905
Pratt & Whitney [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	1,567
Goodwill Resulting from Business Combinations	0
Goodwill - Foreign Currency Translation and Other	(4)
Goodwill - Ending Balance	1,563
Collins Aerospace Systems [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	35,001
Goodwill Resulting from Business Combinations	85
Goodwill - Foreign Currency Translation and Other	132
Goodwill - Ending Balance	35,218
Total Segments [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	48,091
Goodwill Resulting from Business Combinations	93
Goodwill - Foreign Currency Translation and Other	186
Goodwill - Ending Balance	48,370
Eliminations and other [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	21
Goodwill Resulting from Business Combinations	0
Goodwill - Foreign Currency Translation and Other	1
Goodwill - Ending Balance	$ 22