Segment Financial Data (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Net Sales	$ 13,815	$ 13,357
Operating profit	$ 2,267	$ 1,945
Operating profit margin	16.40%	14.60%
Otis [Member]
Segment Reporting Information [Line Items]
Net Sales	$ 2,804	$ 2,715
Operating profit	$ 452	$ 466
Operating profit margin	16.10%	17.20%
UTC Climate, Controls & Security [Member]
Segment Reporting Information [Line Items]
Net Sales	$ 3,892	$ 3,728
Operating profit	$ 963	$ 606
Operating profit margin	24.70%	16.30%
Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Net Sales	$ 3,758	$ 3,588
Operating profit	$ 393	$ 410
Operating profit margin	10.50%	11.40%
UTC Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Net Sales	$ 3,611	$ 3,505
Operating profit	$ 576	$ 538
Operating profit margin	16.00%	15.30%
Total Segments [Member]
Segment Reporting Information [Line Items]
Net Sales	$ 14,065	$ 13,536
Operating profit	$ 2,384	$ 2,020
Operating profit margin	16.90%	14.90%
Eliminations and other [Member]
Segment Reporting Information [Line Items]
Net Sales	$ (250)	$ (179)
Operating profit	(13)	16
General corporate expenses [Member]
Segment Reporting Information [Line Items]
Net Sales	0	0
Operating profit	$ (104)	$ (91)