Contingent Liabilities (Details)	9 Months Ended
	Sep. 30, 2016 USD ($)
Department of Justice Lawsuit Against Pratt and Whitney [Member]
Loss Contingencies [Line Items]
Loss Contingency Lawsuit Filing Date	1999
Loss Contingency Allegations	As previously disclosed, the United States Government sued us in 1999 in the United States District Court for the Southern District of Ohio (District Court), claiming that Pratt & Whitney violated the civil False Claims Act and common law. The claims relate to the "Fighter Engine Competition" between Pratt & Whitney's F100 engine and General Electric's F110 engine. The government alleged that it overpaid for F100 engines under contracts awarded by the U.S. Air Force in fiscal years 1985 through 1990 because Pratt & Whitney inflated its estimated costs for some purchased parts and withheld data that would have revealed the overstatements. At trial, which ended in April 2005, the government claimed Pratt & Whitney's liability to be approximately $624 million.
Loss Contingency Actions Taken By Court Arbitrator Or Mediator	On August 1, 2008, the trial court held that the Air Force had not suffered any actual damages because Pratt & Whitney had made significant price concessions after the alleged overstatements were made. However, the trial court judge found that Pratt & Whitney violated the False Claims Act due to inaccurate statements contained in its 1983 initial engine pricing proposal. In the absence of actual damages, the trial court awarded the government the maximum civil penalty of $7,090,000, or $10,000 for each of the 709 invoices Pratt & Whitney submitted in 1989 and later under the contracts.
Loss Contingency Actions Taken By Plaintiff And Defendant	In September 2008, both the government and UTC appealed the decision to the United States Court of Appeals for the Sixth Circuit. In November 2010, the Sixth Circuit affirmed Pratt & Whitney's liability for the civil penalty under the False Claims Act, but remanded the case to the trial court for further proceedings on the issues of False Claims Act damages and common law liability and damages.
Loss Contingency, Additional Actions Taken by Court, Arbitrator or Mediator	On June 18, 2012, the trial court found that Pratt & Whitney had breached obligations imposed by common law based on the same conduct with respect to which the court previously found liability under the False Claims Act. Under the common law claims, the U.S. Air Force seeks damages for events occurring before March 3, 1989, which are not recoverable under the False Claims Act.
Loss Contingency, Period of Occurrence	fiscal years 1985 through 1990
Loss Contingency Actions Taken By Defendant	On June 17, 2013, the trial court awarded the government approximately $473 million in damages and penalties, plus prejudgment interest in an amount to be determined. On July 1, 2013, the trial court, after determining the amount of prejudgment interest, entered judgment in favor of the government in the amount of approximately $664 million. The trial court also awarded post-judgment interest on the full amount of the judgment to accrue from July 2, 2013, at the federal variable interest rate determined pursuant to 28 U.S.C. § 1961. The judgment included four different components: (1) common law damages of approximately $109 million; (2) prejudgment interest on common law damages of approximately $191 million; (3) False Claims Act treble damages of approximately $357 million; and (4) the civil penalty of approximately $7 million. The penalty component of the judgment previously was affirmed by the United States Court of Appeals in 2010. We filed an appeal from the judgment to the United States Court of Appeals for the Sixth Circuit on August 26, 2013. On April 6, 2015, the Sixth Circuit reversed the trial court’s decision and vacated the prior damages award, noting that the government did not prove any damages. The court rejected as a matter of law the evidence submitted by the government on damages and remanded the case to the District Court to decide in the first instance whether the government should have another opportunity to prove that it suffered any actual damages. On July 17, 2015, the case returned to the District Court, at which time we filed a motion for entry of judgment, seeking a judgment of zero actual damages. The government responded by filing a motion on August 28, 2015, in which it abandoned its claim for actual damages, but sought a judgment of approximately $85 million, representing (1) disgorgement of UTC’s alleged profits in fiscal year 1985, the first year of the multi-year engine competition, (2) prejudgment interest and (3) the approximately $7 million civil penalty
Loss Contingency Settlement Agreement Date	6/2/2016
Loss Contingency, Settlement Agreement, Terms	On June 2, 2016, the District Court rejected the government’s disgorgement calculation, and found that Pratt & Whitney wrongly received $1,176,619 in profits in fiscal year 1985. On June 22, 2016, the District Court entered a judgment in favor of the government in the amount of $11,050,790, comprised of $1,176,619 for profit disgorgement, $2,784,171 for prejudgment interest, and the civil penalty of $7,090,000. Neither party appealed the June 2016 decision. Pratt & Whitney paid the judgment in full in the third quarter, and the matter is concluded.
Loss Contingency, Damages Awarded, Value	$ 11,050,790
U.S. Defense Contract Management Agency Claim Against Pratt & Whitney [Member]
Loss Contingencies [Line Items]
Loss Contingency Lawsuit Filing Date	December 24, 2013
Loss Contingency Allegations	By letter dated December 24, 2013, a Divisional Administrative Contracting Officer of the United States Defense Contract Management Agency asserted a claim and demand for payment of approximately $211 million against Pratt & Whitney. The claim is based on Pratt & Whitney's alleged noncompliance with cost accounting standards from January 1, 2005 to December 31, 2012, due to its method of determining the cost of collaborator parts used in the calculation of material overhead costs for government contracts.
Loss Contingency Damages Sought	$211 million
Loss Contingency Actions Taken By Defendant	On March 18, 2014, Pratt & Whitney filed an appeal to the Armed Services Board of Contract Appeals. Pratt & Whitney’s appeal is still pending, and we continue to believe the government’s claim is without merit.
Asbestos Matter [Member]
Loss Contingencies [Line Items]
Loss Contingency Allegations	As previously reported, like many other industrial companies, we and our subsidiaries have been named as defendants in lawsuits alleging personal injury as a result of exposure to asbestos integrated into certain of our products or business premises. While we have never manufactured asbestos and no longer incorporate it in any currently-manufactured products, certain of our historical products, like those of many other manufacturers, have contained components incorporating asbestos. A substantial majority of these asbestos-related claims have been dismissed without payment or were covered in full or in part by insurance or other forms of indemnity. Additional cases were litigated and settled without any insurance reimbursement. The amounts involved in asbestos related claims were not material individually or in the aggregate in any year.
Loss Contingency, Management's Assessment and Process	Our estimated total liability to resolve all pending and unasserted potential future asbestos claims through 2059 is $378 million and is recorded primarily in Other long-term liabilities on our Condensed Consolidated Balance Sheet as of September 30, 2016. This amount is on a pre-tax basis, not discounted, and excludes the Company’s defense fees (which will continue to be expensed by the Company as they are incurred). In addition, the Company has an insurance recovery receivable for probable asbestos related recoveries of approximately $106 million, which is included primarily in Other assets on our Condensed Consolidated Balance Sheet as of September 30, 2016. In calculating this amount, the Company used the estimated asbestos liability for pending and projected future claims and considered the amount of insurance available, allocation methodologies, solvency ratings, creditworthiness, and the contractual terms with each insurer. The amounts recorded by UTC for asbestos-related claims are based on currently available information and assumptions that we believe are reasonable. Our actual liabilities or insurance recoveries could be higher or lower than those recorded if actual results vary significantly from the assumptions. Key variables in these assumptions include the number and type of new claims to be filed each year, the outcomes or resolution of such claims,the average cost of resolution of each new claim, the resolution of coverage issues with other excess insurance carriers with whom we have not yet achieved settlements, and the solvency risk with respect to our insurance carriers. Other factors that may affect our future liability include uncertainties surrounding the litigation process from jurisdiction to jurisdiction and from case to case, reforms that may be made by state and federal courts, and the passage of state or federal tort reform legislation.
Loss Contingency, Estimate of Possible Loss	$ 378,000,000
Loss Contingency, Receivable	$ 106,000,000
German Tax Office Against Otis [Member]
Loss Contingencies [Line Items]
Loss Contingency Lawsuit Filing Date	August 3, 2012
Loss Contingency Allegations	As previously disclosed, UTC has been involved in administrative review proceedings with the German Tax Office, which concern approximately €215 million (approximately $241 million) of tax benefits that we have claimed related to a 1998 reorganization of the corporate structure of Otis operations in Germany. Upon audit, these tax benefits were disallowed by the German Tax Office. UTC estimates interest associated with the aforementioned tax benefits is an additional approximately €118 million (approximately $133 million). On August 3, 2012, we filed suit in the local German Tax Court (Berlin-Brandenburg). In March 2016, the local German Tax Court dismissed our suit, and we have appealed this decision to the German Federal Tax Court (FTC).
Loss Contingency Actions Taken By Plaintiff And Defendant	From 2008 to 2014, there was ongoing litigation between the German Government and another taxpayer in a case involving a German tax law relevant to our reorganization. In November 2014, the FTC ruled in favor of the German Government, and against the other taxpayer. In light of the FTC decision in the case involving the other taxpayer, we fully accrued for tax and interest in 2014.
Loss Contingency Damages Sought	€215 million (approximately $241 million)
Loss Contingency Actions Taken By Defendant	In 2015, UTC made tax and interest payments to German tax authorities of €275 million (approximately $300 million) in order to avoid additional interest accruals pending final resolution of this matter. In the meantime, we continue to vigorously litigate our matter.
Estimate of interest on tax benefit	€118 million (approximately $133 million)
Loss Contingency, Interest Paid	€275 million (approximately $300 million)