Segment Financial Data (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenues	$ 19,496	$ 16,510	$ 57,495	$ 48,457
Operating Income (Loss)	$ 2,486	$ 1,838	$ 7,115	$ 6,642
Operating Profit Margin	12.80%	11.10%	12.40%	13.70%
Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	$ 5,283	$ 4,789	$ 15,250	$ 13,854
Operating Income (Loss)	$ 471	$ 109	$ 1,328	$ 919
Operating Profit Margin	8.90%	2.30%	8.70%	6.60%
Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	$ 19,907	$ 16,847	$ 58,692	$ 49,483
Operating Income (Loss)	$ 2,831	$ 2,049	$ 8,022	$ 7,191
Operating Profit Margin	14.20%	12.20%	13.70%	14.50%
Otis [Member]
Segment Reporting Information [Line Items]
Revenues	$ 3,307	$ 3,223	$ 9,751	$ 9,604
Operating Income (Loss)	$ 508	$ 486	$ 1,449	$ 1,424
Operating Profit Margin	15.40%	15.10%	14.90%	14.80%
Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	$ 4,822	$ 4,880	$ 14,107	$ 14,291
Operating Income (Loss)	$ 685	$ 844	$ 2,050	$ 3,081
Operating Profit Margin	14.20%	17.30%	14.50%	21.60%
Eliminations and other [Member]
Segment Reporting Information [Line Items]
Revenues	$ (411)	$ (337)	$ (1,197)	$ (1,026)
Operating Income (Loss)	(232)	(102)	(572)	(210)
General corporate expenses [Member]
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Operating Income (Loss)	(113)	(109)	(335)	(339)
Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	6,495	3,955	19,584	11,734
Operating Income (Loss)	$ 1,167	$ 610	$ 3,195	$ 1,767
Operating Profit Margin	18.00%	15.40%	16.30%	15.10%
United States [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	$ 4,184	$ 3,696	$ 11,883	$ 10,469
United States [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	12,377	9,902	36,340	28,522
United States [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	893	864	2,709	2,568
United States [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	2,536	2,537	7,457	7,250
United States [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	4,764	2,805	14,291	8,235
Europe [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	91	141	311	440
Europe [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	3,271	3,046	10,043	9,436
Europe [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	943	968	2,891	3,028
Europe [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	1,313	1,377	3,906	4,216
Europe [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	924	560	2,935	1,752
Asia Pacific [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	258	316	807	996
Asia Pacific [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	2,432	2,257	6,905	6,602
Asia Pacific [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	1,217	1,129	3,393	3,220
Asia Pacific [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	728	726	2,077	2,131
Asia Pacific [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	229	86	628	255
Other [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	750	636	2,249	1,949
Other [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	1,827	1,642	5,404	4,923
Other [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	254	262	758	788
Other [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	245	240	667	694
Other [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	578	504	1,730	1,492
Commercial and industrial, non aerospace [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	44	5	72	31
Commercial and industrial, non aerospace [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	8,185	8,122	23,968	23,970
Commercial and industrial, non aerospace [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	3,307	3,223	9,751	9,604
Commercial and industrial, non aerospace [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	4,822	4,880	14,107	14,291
Commercial and industrial, non aerospace [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	12	14	38	44
Commercial Aerospace [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	3,671	3,421	10,584	9,989
Commercial Aerospace [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	8,394	6,452	24,990	18,955
Commercial Aerospace [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Commercial Aerospace [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Commercial Aerospace [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	4,723	3,031	14,406	8,966
Military aerospace [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	1,568	1,363	4,594	3,834
Military aerospace [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	3,328	2,273	9,734	6,558
Military aerospace [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Military aerospace [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Military aerospace [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	1,760	910	5,140	2,724
Service [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	2,053	2,086	5,742	5,838
Service [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	5,884	5,293	17,050	15,533
Service [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	1,858	1,775	5,511	5,412
Service [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	824	774	2,404	2,374
Service [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	1,149	658	3,393	1,909
Product [Member] | Pratt & Whitney [Member]
Segment Reporting Information [Line Items]
Revenues	3,230	2,703	9,508	8,016
Product [Member] | Total Segments [Member]
Segment Reporting Information [Line Items]
Revenues	14,023	11,554	41,642	33,950
Product [Member] | Otis [Member]
Segment Reporting Information [Line Items]
Revenues	1,449	1,448	4,240	4,192
Product [Member] | Carrier [Member]
Segment Reporting Information [Line Items]
Revenues	3,998	4,106	11,703	11,917
Product [Member] | Collins Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Revenues	$ 5,346	$ 3,297	$ 16,191	$ 9,825