Income Taxes	3 Months Ended
Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	Income Taxes The decrease in the effective tax rate for the quarter ended March 31, 2019 is primarily the result of Tax Cuts and Jobs Act of 2017 (TCJA) interpretive guidance and the absence of a TCJA tax charge recorded in the first quarter of 2018. In addition, the Company recognized a non-cash gain of approximately $40 million, primarily tax, as a result of the closure of a 2014 IRS audit of a subsidiary acquired as part of the Rockwell Collins acquisition. This gain was partially offset by the unfavorable pre-tax impact of a reversal of a related indemnity asset during the quarter of approximately $23 million. We conduct business globally and, as a result, UTC or one or more of our subsidiaries files income tax returns in the U.S. federal jurisdiction and various state and foreign jurisdictions. In the normal course of business we are subject to examination by taxing authorities throughout the world, including such major jurisdictions as Australia, Belgium, Brazil, Canada, China, France, Germany, Hong Kong, India, Italy, Japan, Mexico, Netherlands, Poland, Singapore, South Korea, Spain, Switzerland, the United Kingdom, and the United States. With few exceptions, we are no longer subject to U.S. federal, state and local, or non-U.S. income tax examinations for years before 2008. In the ordinary course of business, there is inherent uncertainty in quantifying our income tax positions. We assess our income tax positions and record tax benefits for all years subject to examination based upon management’s evaluation of the facts, circumstances, and information available at the reporting date. It is reasonably possible that a net reduction within the range of $390 million to $750 million of unrecognized tax benefits may occur within the next 12 months as a result of additional worldwide uncertain tax positions, the closure of tax statutes, or the revaluation of current uncertain tax positions arising from the issuance of legislation, regulatory or other guidance or developments in examinations, in appeals, or in the courts. See Note 15, Contingent Liabilities, for discussion regarding uncertain tax positions, included in the above range, related to pending litigation with respect to certain deductions claimed in Germany. UTC tax years 2014, 2015 and 2016 are currently under review by the Examination Division of the Internal Revenue Service (IRS), which is expected to conclude its review before the end of 2019. During the quarter ended March 31, 2019, the Company recognized a non-cash gain of approximately $40 million, primarily tax, as a result of the closure of an IRS audit of the 2014 tax year of a subsidiary acquired as part of UTC’s acquisition of Rockwell Collins. This gain was partially offset by the unfavorable pre-tax impact of a reversal of a related indemnity asset during the quarter of approximately $23 million. Another subsidiary of the Company is engaged in litigation in Italy which is currently pending before the Italian Supreme Court following favorable lower court decisions. The Italian Tax Authority announced an amnesty program which the Company is currently evaluating. Participation in the amnesty program would be expected to result in the recognition of a non-cash gain, primarily tax, in the range of $90 million to $110 million as early as the second quarter of 2019. The Company will continue to review and incorporate, as necessary, Tax Cuts and Jobs Act of 2017 (TCJA) changes related to forthcoming U.S. Treasury Regulations, other updates, and the finalization of the deemed inclusions to be reported on the Company’s 2018 U.S. federal income tax return.

Income Taxes

The decrease in the effective tax rate for the quarter ended March 31, 2019 is primarily the result of Tax Cuts and Jobs Act of 2017 (TCJA) interpretive guidance and the absence of a TCJA tax charge recorded in the first quarter of 2018. In addition, the Company recognized a non-cash gain of approximately $40 million, primarily tax, as a result of the closure of a 2014 IRS audit of a subsidiary acquired as part of the Rockwell Collins acquisition. This gain was partially offset by the unfavorable pre-tax impact of a reversal of a related indemnity asset during the quarter of approximately $23 million.

We conduct business globally and, as a result, UTC or one or more of our subsidiaries files income tax returns in the U.S. federal jurisdiction and various state and foreign jurisdictions. In the normal course of business we are subject to examination by taxing authorities throughout the world, including such major jurisdictions as Australia, Belgium, Brazil, Canada, China, France, Germany, Hong Kong, India, Italy, Japan, Mexico, Netherlands, Poland, Singapore, South Korea, Spain, Switzerland, the United Kingdom, and the United States. With few exceptions, we are no longer subject to U.S. federal, state and local, or non-U.S. income tax examinations for years before 2008.

In the ordinary course of business, there is inherent uncertainty in quantifying our income tax positions. We assess our income tax positions and record tax benefits for all years subject to examination based upon management’s evaluation of the facts, circumstances, and information available at the reporting date. It is reasonably possible that a net reduction within the range of $390 million to $750 million of unrecognized tax benefits may occur within the next 12 months as a result of additional worldwide uncertain tax positions, the closure of tax statutes, or the revaluation of current uncertain tax positions arising from the issuance of legislation, regulatory or other guidance or developments in examinations, in appeals, or in the courts. See Note 15, Contingent Liabilities, for discussion regarding uncertain tax positions, included in the above range, related to pending litigation with respect to certain deductions claimed in Germany.

UTC tax years 2014, 2015 and 2016 are currently under review by the Examination Division of the Internal Revenue Service (IRS), which is expected to conclude its review before the end of 2019. During the quarter ended March 31, 2019, the Company recognized a non-cash gain of approximately $40 million, primarily tax, as a result of the closure of an IRS audit of the 2014 tax year of a subsidiary acquired as part of UTC’s acquisition of Rockwell Collins. This gain was partially offset by the unfavorable pre-tax impact of a reversal of a related indemnity asset during the quarter of approximately $23 million. Another subsidiary of the Company is engaged in litigation in Italy which is currently pending before the Italian Supreme Court following favorable lower court decisions. The Italian Tax Authority announced an amnesty program which the Company is currently evaluating. Participation in the amnesty program would be expected to result in the recognition of a non-cash gain, primarily tax, in the range of $90 million to $110 million as early as the second quarter of 2019.

The Company will continue to review and incorporate, as necessary, Tax Cuts and Jobs Act of 2017 (TCJA) changes related to forthcoming U.S. Treasury Regulations, other updates, and the finalization of the deemed inclusions to be reported on the Company’s 2018 U.S. federal income tax return.