Segment Financial Data (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Revenues	$ 18,365	$ 15,242
Operating profit	$ 2,045	$ 1,928
Operating Profit Margin	11.10%	12.60%
Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	$ 4,817	$ 4,329
Operating profit	$ 433	$ 413
Operating Profit Margin	9.00%	9.50%
Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	$ 18,749	$ 15,559
Operating profit	$ 2,244	$ 2,043
Operating Profit Margin	12.00%	13.10%
Otis [Member]
Segment Reporting Information [Line Items]
Revenues	$ 3,096	$ 3,037
Operating profit	$ 426	$ 450
Operating Profit Margin	13.80%	14.80%
Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	$ 4,323	$ 4,376
Operating profit	$ 529	$ 592
Operating Profit Margin	12.20%	13.50%
Eliminations and other [Member]
Segment Reporting Information [Line Items]
Revenues	$ (384)	$ (317)
Operating profit	(101)	(11)
General corporate expenses [Member]
Segment Reporting Information [Line Items]
Revenues	0	0
Operating profit	(98)	(104)
Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	6,513	3,817
Operating profit	$ 856	$ 588
Operating Profit Margin	13.10%	15.40%
United States [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	$ 3,732	$ 3,121
United States [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	11,588	8,715
United States [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	912	845
United States [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	2,214	2,095
United States [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	4,730	2,654
Europe [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	108	173
Europe [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	3,379	3,170
Europe [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	955	1,006
Europe [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	1,292	1,384
Europe [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	1,024	607
Asia Pacific [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	255	368
Asia Pacific [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	2,032	2,059
Asia Pacific [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	976	922
Asia Pacific [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	612	685
Asia Pacific [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	189	84
Other [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	722	667
Other [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	1,750	1,615
Other [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	253	264
Other [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	205	212
Other [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	570	472
Commercial and industrial, non aerospace [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	23	21
Commercial and industrial, non aerospace [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	7,456	7,449
Commercial and industrial, non aerospace [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	3,096	3,037
Commercial and industrial, non aerospace [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	4,323	4,376
Commercial and industrial, non aerospace [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	14	15
Commercial Aerospace [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	3,375	3,199
Commercial Aerospace [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	8,203	6,110
Commercial Aerospace [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	0	0
Commercial Aerospace [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	0	0
Commercial Aerospace [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	4,828	2,911
Military aerospace [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	1,419	1,109
Military aerospace [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	3,090	2,000
Military aerospace [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	0	0
Military aerospace [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	0	0
Military aerospace [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	1,671	891
Service [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	1,844	1,792
Service [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	5,525	5,018
Service [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	1,817	1,818
Service [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	757	779
Service [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	1,107	629
Product [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	2,973	2,537
Product [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	13,224	10,541
Product [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	1,279	1,219
Product [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	3,566	3,597
Product [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	$ 5,406	$ 3,188