Acquisition, Dispositions, Goodwill and Other Intangible Assets (Goodwill) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2016 USD ($)
Goodwill [Line Items]
Goodwill - Beginning Balance	$ 27,301
Goodwill Resulting from Business Combinations	493
Goodwill - Foreign Currency Translation and Other	(259)
Goodwill - Ending Balance	27,535
Otis [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	1,566
Goodwill Resulting from Business Combinations	15
Goodwill - Foreign Currency Translation and Other	3
Goodwill - Ending Balance	1,584
UTC Climate, Controls & Security [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	9,458
Goodwill Resulting from Business Combinations	453
Goodwill - Foreign Currency Translation and Other	(143)
Goodwill - Ending Balance	9,768
Pratt & Whitney [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	1,515
Goodwill Resulting from Business Combinations	0
Goodwill - Foreign Currency Translation and Other	(1)
Goodwill - Ending Balance	1,514
UTC Aerospace Systems [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	14,759
Goodwill Resulting from Business Combinations	25
Goodwill - Foreign Currency Translation and Other	(118)
Goodwill - Ending Balance	14,666
Total Segments [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	27,298
Goodwill Resulting from Business Combinations	493
Goodwill - Foreign Currency Translation and Other	(259)
Goodwill - Ending Balance	27,532
Eliminations and other [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	3
Goodwill Resulting from Business Combinations	0
Goodwill - Foreign Currency Translation and Other	0
Goodwill - Ending Balance	$ 3