Performance Graph - Unaudited (Tables)	12 Months Ended
Dec. 31, 2018
Performance Graph [Abstract]
Cumulative Total Shareholder Return [Table Text Block]	COMPARISON OF CUMULATIVE FIVE YEAR TOTAL RETURN

Tabular disclosure of the cumulative total shareholder return for the current year baselined to five years prior.

No definition available.

Name:	utx_CumulativeTotalShareholderReturnTableTextBlock
Namespace Prefix:	utx_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration