Basis of Presentation	6 Months Ended
Mar. 31, 2026
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, 2025 filed with the SEC on November 14, 2025. The results of operations for the three and six month periods ended March 31, 2026 are not necessarily indicative of results for the Company’s 2026 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, a global leader in thermal management, mission-critical building systems, energy efficiency, and decarbonization, helps customers use energy more productively, reduce carbon emissions, and operate with the precision and resilience required in rapidly expanding industries such as data centers, healthcare, pharmaceuticals, advanced manufacturing, and higher education. 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 capabilities, to deliver solutions and services addressing distinct and diverse operating environments and regulatory requirements that address customers’ needs in their core missions. 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. Prior Period Revision – Statement of Cash Flows Amounts reported as "Repayments of debt" and "Proceeds from debt" have been revised for certain short-term debt transactions that occurred in the six months ended March 31, 2025 and were incorrectly presented on a net basis within the financing activities section of the consolidated statements of cash flows. A similar revision for the nine months ended June 30, 2025 will be included in the Company's third quarter fiscal 2026 Quarterly Report on Form 10-Q. Cash provided by financing activities and the total increase (decrease) in cash, cash equivalents and restricted cash were unchanged for all affected periods. The Company does not consider the incorrect presentation to be material to any periods impacted.

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, 2025 filed with the SEC on November 14, 2025. The results of operations for the three and six month periods ended March 31, 2026 are not necessarily indicative of results for the Company’s 2026 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, a global leader in thermal management, mission-critical building systems, energy efficiency, and decarbonization, helps customers use energy more productively, reduce carbon emissions, and operate with the precision and resilience required in rapidly expanding industries such as data centers, healthcare, pharmaceuticals, advanced manufacturing, and higher education.

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 capabilities, to deliver solutions and services addressing distinct and diverse operating environments and regulatory requirements that address customers’ needs in their core missions.

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.