Acquisition, Dispositions, Goodwill and Other Intangible Assets (Goodwill) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Goodwill [Line Items]
Goodwill - Beginning Balance	$ 28,168
Goodwill resulting from business combinations	11
Goodwill translation and other	37
Goodwill - Ending Balance	28,216
Otis [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	1,741
Goodwill resulting from business combinations	11
Goodwill translation and other	(10)
Goodwill - Ending Balance	1,742
UTC Climate Controls and Security [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	9,727
Goodwill resulting from business combinations	0
Goodwill translation and other	30
Goodwill - Ending Balance	9,757
UTC Aerospace Systems [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	15,069
Goodwill resulting from business combinations	0
Goodwill translation and other	17
Goodwill - Ending Balance	15,086
Pratt and Whitney [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	1,273
Goodwill resulting from business combinations	0
Goodwill translation and other	0
Goodwill - Ending Balance	1,273
Sikorsky [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	353
Goodwill resulting from business combinations	0
Goodwill translation and other	0
Goodwill - Ending Balance	353
Total Segments [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	28,163
Goodwill resulting from business combinations	11
Goodwill translation and other	37
Goodwill - Ending Balance	28,211
Eliminations and other [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	5
Goodwill resulting from business combinations	0
Goodwill translation and other	0
Goodwill - Ending Balance	$ 5