Basis of Presentation	9 Months Ended
Jun. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	BASIS OF PRESENTATION The consolidated financial statements include the consolidated accounts of Johnson Controls International plc, a public limited company organized under the laws of Ireland, and its subsidiaries (Johnson Controls International plc and all its subsidiaries, hereinafter collectively referred to as the "Company" or "Johnson Controls"). In the opinion of management, the accompanying unaudited consolidated financial statements contain all adjustments (which include normal recurring adjustments) necessary to state fairly the financial position, results of operations and cash flows for the periods presented. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") have been omitted pursuant to the rules and regulations of the United States Securities and Exchange Commission ("SEC"). These consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto included in the Company's Annual Report on Form 10-K for the year ended September 30, 2024 filed with the SEC on November 19, 2024. The results of operations for the three and nine month periods ended June 30, 2025 are not necessarily indicative of results for the Company’s 2025 fiscal year because of seasonal and other factors. On April 1, 2025, the Company realigned into three reportable segments (Americas, EMEA and APAC) from four reportable segments (Global Products, Building Solutions North America, Building Solutions EMEA/LA and Building Solutions APAC). Historical information has been recast to present the comparative periods on a consistent basis. Refer to Note 16, "Segment Information," of the notes to the consolidated financial statements for further disclosure. Nature of Operations Johnson Controls International plc, headquartered in Cork, Ireland, is a global leader in smart, safe, healthy and sustainable buildings, serving a wide range of customers around the globe. The Company’s products and solutions advance the safety, comfort and intelligence of spaces to serve people, places and the planet. The Company is committed to helping its customers win and creating greater value for all of its stakeholders through its strategic focus on buildings. The Company is a global leader in engineering, manufacturing, commissioning and retrofitting building products and systems, including commercial heating, ventilating, air-conditioning ("HVAC") equipment, industrial refrigeration systems, controls, security systems, fire-detection systems and fire-suppression solutions. The Company further serves customers by providing technical services, including maintenance, management, repair, retrofit and replacement of equipment (in the HVAC, industrial refrigeration, controls, security and fire-protection space) and energy-management consulting. The Company partners with customers by leveraging its broad product portfolio and digital capabilities, together with its direct channel service and solutions capabilities, to deliver outcome-based solutions across the lifecycle of a building that address customers’ needs to improve energy efficiency, enhance security, create healthy environments and reduce greenhouse gas emissions. As discussed in more detail in Note 3, "Assets and Liabilities Held for Sale and Discontinued Operations", of the notes to the consolidated financial statements, the Company entered into a definitive agreement to sell its Residential and Light Commercial (“R&LC") HVAC business, including the North America Ducted business and the global Residential joint venture with Hitachi Global Life Solutions, Inc. (“Hitachi”), of which Johnson Controls owns 60% and Hitachi owns 40%. The R&LC HVAC business, which was previously reported in the Global Products segment prior to the Company's resegmentation, meets the criteria to be classified as a discontinued operation and, as a result, its historical financial results are reflected in the consolidated financial statements as a discontinued operation, and assets and liabilities are classified as held for sale for all periods presented. Unless otherwise noted, all activities and amounts reported in the following footnotes relate to the continuing operations of the Company and exclude activities and amounts related to the R&LC HVAC business. Principles of Consolidation The consolidated financial statements include the consolidated accounts of Johnson Controls International plc and its subsidiaries in conformity with U.S. GAAP. The results of companies acquired or disposed of during the reporting period are included in the consolidated financial statements from the effective date of acquisition or up to the date of disposal. Investments in partially-owned affiliates are accounted for by the equity method when the Company exercises significant influence, which typically occurs when its ownership interest exceeds 20%, and the Company does not have a controlling interest. The Company consolidates variable interest entities ("VIE") when it has the power to direct the significant activities of the entity and the obligation to absorb losses or receive benefits from the entity that may be significant. The Company did not have any material consolidated or nonconsolidated VIE's for the presented reporting periods.

The consolidated financial statements include the consolidated accounts of Johnson Controls International plc, a public limited company organized under the laws of Ireland, and its subsidiaries (Johnson Controls International plc and all its subsidiaries, hereinafter collectively referred to as the "Company" or "Johnson Controls"). In the opinion of management, the accompanying unaudited consolidated financial statements contain all adjustments (which include normal recurring adjustments) necessary to state fairly the financial position, results of operations and cash flows for the periods presented. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") have been omitted pursuant to the rules and regulations of the United States Securities and Exchange Commission ("SEC"). These consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto included in the Company's Annual Report on Form 10-K for the year ended September 30, 2024 filed with the SEC on November 19, 2024. The results of operations for the three and nine month periods ended June 30, 2025 are not necessarily indicative of results for the Company’s 2025 fiscal year because of seasonal and other factors.

On April 1, 2025, the Company realigned into three reportable segments (Americas, EMEA and APAC) from four reportable segments (Global Products, Building Solutions North America, Building Solutions EMEA/LA and Building Solutions APAC). Historical information has been recast to present the comparative periods on a consistent basis. Refer to Note 16, "Segment Information," of the notes to the consolidated financial statements for further disclosure.

Johnson Controls International plc, headquartered in Cork, Ireland, is a global leader in smart, safe, healthy and sustainable buildings, serving a wide range of customers around the globe. The Company’s products and solutions advance the safety, comfort and intelligence of spaces to serve people, places and the planet. The Company is committed to helping its customers win and creating greater value for all of its stakeholders through its strategic focus on buildings.

The Company is a global leader in engineering, manufacturing, commissioning and retrofitting building products and systems, including commercial heating, ventilating, air-conditioning ("HVAC") equipment, industrial refrigeration systems, controls, security systems, fire-detection systems and fire-suppression solutions. The Company further serves customers by providing technical services, including maintenance, management, repair, retrofit and replacement of equipment (in the HVAC, industrial refrigeration, controls, security and fire-protection space) and energy-management consulting. The Company partners with customers by leveraging its broad product portfolio and digital capabilities, together with its direct channel service and solutions capabilities, to deliver outcome-based solutions across the lifecycle of a building that address customers’ needs to improve energy efficiency, enhance security, create healthy environments and reduce greenhouse gas emissions.

As discussed in more detail in Note 3, "Assets and Liabilities Held for Sale and Discontinued Operations", of the notes to the consolidated financial statements, the Company entered into a definitive agreement to sell its Residential and Light Commercial (“R&LC") HVAC business, including the North America Ducted business and the global Residential joint venture with Hitachi Global Life Solutions, Inc. (“Hitachi”), of which Johnson Controls owns 60% and Hitachi owns 40%. The R&LC HVAC business, which was previously reported in the Global Products segment prior to the Company's resegmentation, meets the criteria to be classified as a discontinued operation and, as a result, its historical financial results are reflected in the consolidated financial statements as a discontinued operation, and assets and liabilities are classified as held for sale for all periods presented. Unless otherwise noted, all activities and amounts reported in the following footnotes relate to the continuing operations of the Company and exclude activities and amounts related to the R&LC HVAC business.

The consolidated financial statements include the consolidated accounts of Johnson Controls International plc and its subsidiaries in conformity with U.S. GAAP. The results of companies acquired or disposed of during the reporting period are included in the consolidated financial statements from the effective date of acquisition or up to the date of disposal.

The Company consolidates variable interest entities ("VIE") when it has the power to direct the significant activities of the entity and the obligation to absorb losses or receive benefits from the entity that may be significant. The Company did not have any material consolidated or nonconsolidated VIE's for the presented reporting periods.