Acquisitions and Divestitures (Details) - Silent Aire Acquisition - USD ($) $ in Millions	3 Months Ended
Jun. 30, 2021	Sep. 30, 2020
Acquisitions And Divestitures [Line Items]
Goodwill	$ 18,445	$ 17,932
Global Products
Acquisitions And Divestitures [Line Items]
Goodwill	5,886	$ 5,579
Silent-Aire
Acquisitions And Divestitures [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables	141
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory	61
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other	3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	33
Goodwill	235
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	499
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	83
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	1,060
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable	62
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accrued Compensation and Benefits	5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue	32
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other	10
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other	195
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	304
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	756
Silent-Aire \| Trademarks/trade names
Acquisitions And Divestitures [Line Items]
Indefinite-lived Intangible Assets	77
Silent-Aire \| Customer Relationships
Acquisitions And Divestitures [Line Items]
Finite-lived Intangible Assets Acquired	$ 275
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	19 years
Silent-Aire \| Technology-Based Intangible Assets
Acquisitions And Divestitures [Line Items]
Finite-lived Intangible Assets Acquired	$ 126
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	13 years
Silent-Aire \| Miscellaneous
Acquisitions And Divestitures [Line Items]
Finite-lived Intangible Assets Acquired	$ 21
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	1 year

Acquisitions And Discontinued Operations [Line Items]

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Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accrued Compensation and Benefits

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Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of assets acquired at the acquisition date.

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Amount of currency on hand as well as demand deposits with banks or financial institutions, acquired at the acquisition date. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Amount of other assets expected to be realized or consumed before one year or the normal operating cycle, if longer, acquired at the acquisition date.

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Amount due from customers or clients for goods or services, including trade receivables, that have been delivered or sold in the normal course of business, and amounts due from others, including related parties expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer, acquired at the acquisition date.

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Amount of liabilities incurred for goods and services received that are used in an entity's business and related party payables, assumed at the acquisition date.

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Amount of deferred revenue expected to be recognized as such within one year or the normal operating cycle, if longer, assumed at the acquisition date.

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Amount of other liabilities due within one year or within the normal operating cycle, if longer, assumed at the acquisition date.

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Amount of intangible assets, excluding goodwill, acquired at the acquisition date.

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The amount of inventory recognized as of the acquisition date.

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Amount of liabilities assumed at the acquisition date.

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Amount recognized as of the acquisition date for the identifiable assets acquired in excess of (less than) the aggregate liabilities assumed.

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Amount of other liabilities due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

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Amount of other assets expected to be realized or consumed after one year or the normal operating cycle, if longer, acquired at the acquisition date.

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The amount of property, plant, and equipment recognized as of the acquisition date.

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Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, from an acquisition.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase in assets, excluding financial assets and goodwill, lacking physical substance with an indefinite life, from an acquisition.

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