Basis of Presentation and Accounting Policies (Policies)	9 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Receivables	ReceivablesWe record an allowance for doubtful accounts based on customer-specific analysis and general matters such as current assessments of past due balances, historic writeoff experience, and economic conditions and expected changes in market conditions. Receivables are stated net of an allowance for doubtful accounts
Goodwill	Goodwill We perform our annual evaluation of goodwill and indefinite life intangible assets for impairment as required under accounting principles generally accepted in the United States (U.S. GAAP) during the second quarter of each year, or more frequently if events or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying value. Any excess in carrying value over the estimated fair value is charged to results of operations. For our annual evaluation of goodwill, we may perform a qualitative test to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount in order to determine whether it is necessary to perform a quantitative goodwill impairment test. Our reporting units for goodwill evaluation consist of the Intelligent Devices segment, the Software & Control segment, the Lifecycle Services segment (excluding Sensia), and Sensia. When performing the quantitative goodwill impairment test, we determine the fair value of each reporting unit under a combination of an income approach derived from discounted cash flows and a market multiples approach using selected comparable public companies. Significant assumptions used in the income approach include: management’s forecasted cash flows, including estimated future revenue growth rates and margins, discount rates, and terminal value. Forecasts of future revenue growth and margins are based on management’s best estimates. Discount rates are determined using a weighted average cost of capital adjusted for risk factors specific to the reporting unit, with comparison to market and industry data. The terminal value is estimated following the common methodology of calculating the present value of estimated perpetual cash flow beyond the last projected period assuming constant discount and long-term growth rates. Significant assumptions used in the market multiples approach include selection of the comparable public companies and calculation of the appropriate market multiples. Demand for Sensia hardware and software products, solutions and services is sensitive to industry volatility and risks, including those related to commodity prices, supply and demand dynamics, production costs, geological activity, and political activities. Actual results and forecasts of revenue growth and margins for our Sensia reporting unit may be impacted by its concentration within the Oil & Gas industry and with its customer base.
Leases	Leases We have operating leases primarily for real estate, vehicles, and equipment. We determine if a contract is, or contains, a lease at contract inception. A right-of-use (ROU) asset and a corresponding lease liability are recognized at commencement for contracts that are, or contain, a lease with an original term greater than 12 months. ROU assets represent our right to use an underlying asset during the lease term, including periods for which renewal options are reasonably certain to be exercised, and lease liabilities represent our obligation to make lease payments arising from the lease. Lease expense is recognized on a straight-line basis over the lease term for operating leases with an original term of 12 months or less. Some leasing arrangements require variable payments that are dependent on usage or may vary for other reasons, such as payments for insurance and tax payments. A portion of our real estate leases is generally subject to annual changes based upon an index. The changes based upon the index are treated as variable lease payments. The variable portion of lease payments is not included in our ROU assets or lease liabilities and is expensed when incurred. We elected to not separate lease and nonlease components of contracts for all underlying asset classes. Accordingly, all expenses associated with a lease contract are accounted for as lease expenses. Lease liabilities are recognized at the contract commencement date based on the present value of remaining lease payments over the lease term. To calculate the lease liabilities we use our incremental borrowing rate. We determine our incremental borrowing rate at the commencement date using our unsecured borrowing rate, adjusted for collateralization and lease term. For leases denominated in a currency other than the U.S. dollar, the collateralized borrowing rate in the foreign currency is determined using the U.S. dollar and foreign currency swap spread. Long-term lease liabilities are presented as operating lease liabilities and current lease liabilities are included in other current liabilities in the Consolidated Balance Sheet. ROU assets are recognized at the contract commencement date at the value of the related lease liability, adjusted for any prepayments, lease incentives received and initial direct costs incurred. Operating lease ROU assets are presented as operating lease right-of-use assets in the Consolidated Balance Sheet. Lease expenses for operating leases are recognized on a straight-line basis over the lease term and recorded in cost of sales and selling, general and administrative expenses in the Consolidated Statement of Operations.
Recent Accounting Pronouncements	Recently Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (FASB) issued a new standard on accounting for leases that requires lessees to recognize right-of-use assets and lease liabilities for most leases, among other changes to existing lease accounting guidance. The new standard also requires additional qualitative and quantitative disclosures about leasing activities. We adopted the new standard using the modified retrospective transition method, which resulted in an immaterial cumulative-effect adjustment to the opening balance of retained earnings as of October 1, 2019, our adoption date. The amounts of lease right-of-use assets and corresponding lease liabilities recorded in the Consolidated Balance Sheet upon adoption were $316 million and $329 million, respectively. We have implemented necessary changes to accounting policies, processes, controls and systems to enable compliance with this new standard. In February 2018, the FASB issued a new standard regarding the reporting of comprehensive loss, which gives entities the option to reclassify tax effects of the Tax Cuts and Jobs Act of 2017 (the "Tax Act") stranded in accumulated other comprehensive loss into retained earnings. We adopted the new standard as of October 1, 2019, and elected to reclassify tax effects of $147 million from accumulated other comprehensive loss into retained earnings. In June 2016, the FASB issued a new standard that requires companies to utilize a current expected credit losses impairment (CECL) model for certain financial assets, including trade and other receivables. The CECL model requires that estimated expected credit losses, including allowance for doubtful accounts, consider a broader range of information such as economic conditions and expected changes in market conditions. We adopted the new standard as of October 1, 2020. The adoption of this standard did not have a material impact on our Consolidated Financial Statements.
Income Taxes	Income TaxesAt the end of each interim period, we estimate a base effective tax rate that we expect for the full fiscal year based on our most recent forecast of pre-tax income, permanent book and tax differences and global tax planning strategies. We use this base rate to provide for income taxes on a year-to-date basis, excluding the effect of significant unusual items and items that are reported net of their related tax effects in the period in which they occur.

Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.