Acquisition, Dispositions, Goodwill and Other Intangible Assets (Goodwill) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($)
Goodwill [Line Items]
Goodwill - Beginning Balance	$ 48,063
Goodwill Resulting from Business Combinations	0
Goodwill - Foreign Currency Translation and Other	(582)
Goodwill - Ending Balance	47,481
Impairment of Intangible Asset, Tradename	40
Other Expense [Member]
Goodwill [Line Items]
Portfolio separation costs	1,437
Otis [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	1,647
Goodwill Resulting from Business Combinations	0
Goodwill - Foreign Currency Translation and Other	(39)
Goodwill - Ending Balance	1,608
Carrier [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	9,807
Goodwill Resulting from Business Combinations	0
Goodwill - Foreign Currency Translation and Other	(208)
Goodwill - Ending Balance	9,599
Pratt & Whitney [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	1,563
Goodwill Resulting from Business Combinations	0
Goodwill - Foreign Currency Translation and Other	0
Goodwill - Ending Balance	1,563
Collins Aerospace Systems [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	35,025
Goodwill Resulting from Business Combinations	0
Goodwill - Foreign Currency Translation and Other	(335)
Goodwill - Ending Balance	34,690
Fair Value in Excess of Net Book Value, Amount	$ 1,500
Fair Value in Excess of Net Book Value, Percent	15.00%
Total Segments [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	$ 48,042
Goodwill Resulting from Business Combinations	0
Goodwill - Foreign Currency Translation and Other	(582)
Goodwill - Ending Balance	47,460
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