Acquisition, Dispositions, Goodwill and Other Intangible Assets (Goodwill) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Goodwill [Line Items]
Goodwill - Beginning Balance	$ 28,168
Goodwill Resulting from Business Combinations	241
Goodwill - Foreign Currency Translation and Other	(240)
Goodwill - Ending Balance	28,169
Otis [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	1,741
Goodwill Resulting from Business Combinations	21
Goodwill - Foreign Currency Translation and Other	(48)
Goodwill - Ending Balance	1,714
UTC Climate, Controls and Security [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	9,727
Goodwill Resulting from Business Combinations	11
Goodwill - Foreign Currency Translation and Other	(133)
Goodwill - Ending Balance	9,605
Pratt and Whitney [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	1,273
Goodwill Resulting from Business Combinations	209
Goodwill - Foreign Currency Translation and Other	0
Goodwill - Ending Balance	1,482
UTC Aerospace Systems [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	15,069
Goodwill Resulting from Business Combinations	0
Goodwill - Foreign Currency Translation and Other	(55)
Goodwill - Ending Balance	15,014
Sikorsky [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	353
Goodwill Resulting from Business Combinations	0
Goodwill - Foreign Currency Translation and Other	(4)
Goodwill - Ending Balance	349
Total Segments [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	28,163
Goodwill Resulting from Business Combinations	241
Goodwill - Foreign Currency Translation and Other	(240)
Goodwill - Ending Balance	28,164
Eliminations and other [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	5
Goodwill Resulting from Business Combinations	0
Goodwill - Foreign Currency Translation and Other	0
Goodwill - Ending Balance	$ 5