Segment Financial Data (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Total net sales	$ 14,874	$ 14,690	$ 28,231	$ 28,010
Operating profit	$ 2,337	$ 2,415	$ 4,282	$ 4,597
Operating profit margin	15.70%	16.40%	15.20%	16.40%
Otis [Member]
Segment Reporting Information [Line Items]
Total net sales	$ 3,097	$ 3,098	$ 5,812	$ 5,843
Operating profit	$ 581	$ 627	$ 1,047	$ 1,154
Operating profit margin	18.80%	20.20%	18.00%	19.80%
UTC Climate, Controls & Security [Member]
Segment Reporting Information [Line Items]
Total net sales	$ 4,459	$ 4,454	$ 8,187	$ 8,306
Operating profit	$ 872	$ 823	$ 1,478	$ 1,552
Operating profit margin	19.60%	18.50%	18.10%	18.70%
Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Total net sales	$ 3,813	$ 3,677	$ 7,401	$ 7,009
Operating profit	$ 386	$ 487	$ 796	$ 906
Operating profit margin	10.10%	13.20%	10.80%	12.90%
UTC Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Total net sales	$ 3,716	$ 3,632	$ 7,221	$ 7,180
Operating profit	$ 582	$ 580	$ 1,120	$ 1,149
Operating profit margin	15.70%	16.00%	15.50%	16.00%
Total Segments [Member]
Segment Reporting Information [Line Items]
Total net sales	$ 15,085	$ 14,861	$ 28,621	$ 28,338
Operating profit	$ 2,421	$ 2,517	$ 4,441	$ 4,761
Operating profit margin	16.00%	16.90%	15.50%	16.80%
Eliminations and other [Member]
Segment Reporting Information [Line Items]
Total net sales	$ (211)	$ (171)	$ (390)	$ (328)
Operating profit	13	18	29	66
General corporate expenses [Member]
Segment Reporting Information [Line Items]
Total net sales	0	0	0	0
Operating profit	$ (97)	$ (120)	$ (188)	$ (230)