Document and Entity Information (USD $)
9 Months Ended
Sep. 30, 2011
Jun. 30, 2011
Document and Entity Information [Abstract]  
Document Type10-Q 
Document Period End DateSep. 30, 2011
Amendment Flagfalse 
Document Fiscal Year Focus2011 
Document Fiscal Period FocusQ3 
Current Fiscal Year End Date--12-31 
Entity Registrant NameUNITED TECHNOLOGIES CORP /DE/ 
Entity Central Index Key0000101829 
Entity Well-known Seasoned IssuerYes 
Entity Voluntary FilersNo 
Entity Current Reporting StatusYes 
Entity Filer CategoryLarge Accelerated Filer 
Entity Public Float $ 80,344,177,683
Entity Common Stock, Shares Outstanding906,087,669