Document and Entity Information	6 Months Ended
	Jun. 30, 2019 shares
Document and Entity Information [Abstract]
Entity Incorporation, State or Country Code	DE
Document Type	10-Q
Document Period End Date	Jun. 30, 2019
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Entity Registrant Name	UNITED TECHNOLOGIES CORP /DE/
Entity Central Index Key	0000101829
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Common Stock, Shares Outstanding	862,831,280
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Entity Tax Identification Number	06-0570975
City Area Code	860
Local Phone Number	728-7000
Entity Address, Address Line One	10 Farm Springs Road
Entity Address, City or Town	Farmington
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06032
Entity File Number	1-812
Entity Interactive Data Current	Yes
Document Quarterly Report	true
Document Transition Report	false