The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Basis of Presentation (Details) - segment		3 Months Ended	9 Months Ended
Basis of Presentation (Details) - segment	Apr. 01, 2025	Mar. 31, 2025	Jun. 30, 2025	Jul. 31, 2024
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of reportable segments	3	4	3
Johnson Controls - Hitachi Air Conditioning Holding (UK) Ltd
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage			60.00%	60.00%
Johnson Controls - Hitachi Air Conditioning Holding (UK) Ltd \| Hitachi Global Life Solutions, Inc.
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage			40.00%	40.00%