Document and Entity Information - USD ($)	3 Months Ended
	Mar. 31, 2019	Jun. 30, 2018
Document and Entity Information [Abstract]
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
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 Public Float		$ 99,985,852,722
Entity Common Stock, Shares Outstanding	862,291,415
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes