Accounting Changes (Policies)	6 Months Ended
Accounting Changes (Policies)	Mar. 31, 2019
Accounting Changes and Error Corrections [Abstract]
New Accounting Principle Not Yet Adopted	New Accounting Principles Adopted On October 1, 2018, the Company adopted Accounting Standards Codification Topic 606, "Revenue from Contracts with Customers" ("ASC 606") using the modified retrospective method. Under ASC 606, revenue is recognized upon the transfer of control of goods or services to customers and reflects the amount of consideration to which a reporting entity expects to be entitled in exchange for those goods or services. The Company assessed the impact of this new standard on its consolidated financial statements based upon a review of contracts that were not completed as of October 1, 2018. Amounts presented in the Company's financial statements for the prior-year periods have not been revised and are reflective of the revenue recognition requirements which were in effect for those periods. This accounting standard adoption, which is further discussed in Note 6, did not materially impact any line items of the Company's consolidated income statements and balance sheet. On October 1, 2018, the Company retrospectively adopted an accounting standard update which requires all components of net periodic pension and postretirement benefit costs to be disaggregated from the service cost component and to be presented on the income statement outside a subtotal of income from operations, if one is presented. Upon the Company's adoption of the accounting standard update, which did not have a material impact on its consolidated financial statements, all components of the Company’s net periodic pension and postretirement benefit costs, aside from service cost, are recorded to Other income (expense), net on its consolidated income statements for all periods presented. Revisions of prior-year period amounts were estimated based upon previously disclosed amounts. On October 1, 2018, the Company adopted an accounting standard update which requires that the income tax effects of intercompany sales or transfers of assets, except those involving inventory, be recognized in the income statement as income tax expense (or benefit) in the period that the sale or transfer occurs. The Company adopted this accounting standard update, which did not have a material impact on its consolidated financial statements, using the modified retrospective method. New Accounting Principle Not Yet Adopted In February 2016, the FASB issued a new lease accounting standard which requires lessees to recognize lease assets and lease liabilities on the balance sheet. The new standard also requires expanded disclosures regarding leasing arrangements. The Company will adopt the standard on October 1, 2019 and continues to evaluate the impact on its consolidated financial statements.
Commitments and Contingencies	Given the uncertain nature of litigation generally, the Company is not able, in all cases, to estimate the amount or range of loss that could result from an unfavorable outcome of the litigation to which the Company is a party. In accordance with U.S. GAAP, the Company establishes accruals to the extent probable future losses are estimable (in the case of environmental matters, without considering possible third-party recoveries). With respect to putative class action lawsuits in the United States and certain of the Canadian lawsuits described below relating to product liability matters, the Company is unable to estimate a range of reasonably possible losses for the following reasons: (i) all or certain of the proceedings are in early stages; (ii) the Company has not received and reviewed complete information regarding all or certain of the plaintiffs and their medical conditions; and/or (iii) there are significant factual issues to be resolved. In addition, there is uncertainty as to the likelihood of a class being certified or the ultimate size of the class. With respect to the investigative subpoena issued by the Department of Defense Inspector General and the Department of Health and Human Services and the civil investigative demand served by the Department of Justice, as discussed below, the Company is unable to estimate a range of reasonably possible losses for the following reasons: (i) all or certain of the proceedings are in early stages; and/or (ii) there are significant factual and legal issues to be resolved. In view of the uncertainties discussed below, the Company could incur charges in excess of any currently established accruals and, to the extent available, liability insurance. In the opinion of management, any such future charges, individually or in the aggregate, could have a material adverse effect on the Company’s consolidated results of operations and consolidated cash flows.
Revenue	Timing of Revenue Recognition The Company's revenues are primarily recognized when the customer obtains control of the product sold, which is generally upon shipment or delivery, depending on the delivery terms specified in the sales agreement. Revenues associated with certain instruments and equipment for which installation is complex, and therefore significantly affects the customer’s ability to use and benefit from the product, are recognized when customer acceptance of these installed products has been confirmed. For certain service arrangements, including extended warranty and software maintenance contracts, revenue is recognized ratably over the contract term. The majority of revenues relating to extended warranty contracts associated with certain instruments and equipment is generally recognized within a few years whereas deferred revenue relating to software maintenance contracts is generally recognized over a longer period. Measurement of Revenues The Company acts as the principal in substantially all of its customer arrangements and as such, generally records revenues on a gross basis. Revenues exclude any taxes that the Company collects from customers and remits to tax authorities. The Company considers its shipping and handling costs to be costs of contract fulfillment and has made the accounting policy election to record these costs within Selling and administrative expense. Payment terms extended to the Company's customers are based upon commercially reasonable terms for the markets in which the Company's products are sold. Because the Company generally expects to receive payment within one year or less from when control of a product is transferred to the customer, the Company does not generally adjust its revenues for the effects of a financing component. The Company’s estimate of probable credit losses relating to trade receivables is determined based on historical experience and other specific account data. Amounts are written off against the allowances for doubtful accounts when the Company determines that a customer account is uncollectible. Such amounts are not material to the Company's consolidated financial results. The Company's gross revenues are subject to a variety of deductions which are recorded in the same period that the underlying revenues are recognized. Such variable consideration include rebates, sales discounts and sales returns. Because these deductions represent estimates of the related obligations, judgment is required when determining the impact of these revenue deductions on gross revenues for a reporting period. Rebates provided by the Company are based upon prices determined under the Company's agreements with its end-user customers. Additional factors considered in the estimate of the Company's rebate liability include the quantification of inventory that is either in stock at or in transit to the Company's distributors, as well as the estimated lag time between the sale of product and the payment of corresponding rebates. The impact of other forms of variable consideration, including sales discounts and sales returns, is not material to the Company's revenues. The Company's agreements with customers within certain organizational units including Medication Management Solutions, Diagnostic Systems and Biosciences, contain multiple performance obligations including both products and certain services noted above. The transaction price for these agreements is allocated to each performance obligation based upon its relative standalone selling price. Standalone selling price is the amount at which the Company would sell a promised good or service separately to a customer. The Company generally estimates standalone selling prices using its list prices and a consideration of typical discounts offered to customers.
Derivatives	Hedges of the transactional foreign exchange exposures resulting primarily from intercompany payables and receivables are undesignated hedges. The Company uses derivative instruments to mitigate certain exposures. The Company does not enter into derivative financial instruments for trading or speculative purposes. The effects these derivative instruments and hedged items have on financial position, financial performance, and cash flows are provided below. The Company’s policy is to manage interest cost using a mix of fixed and variable rate debt. The Company periodically uses interest rate swaps to manage such exposures. Under these interest rate swaps, the Company exchanges, at specified intervals, the difference between fixed and floating interest amounts calculated by reference to an agreed-upon notional principal amount. These swaps are designated as either fair value or cash flow hedges. For interest rate swaps designated as fair value hedges (i.e., hedges against the exposure to changes in the fair value of an asset or a liability or an identified portion thereof that is attributable to a particular risk), changes in the fair value of the interest rate swaps offset changes in the fair value of the fixed rate debt due to changes in market interest rates. Changes in the fair value of the interest rate swaps designated as cash flow hedges (i.e., hedging the exposure to variability in expected future cash flows that is attributable to a particular risk) are offset by amounts recorded in Other comprehensive income (loss). If interest rate derivatives designated as cash flow hedges are terminated, the balance in Accumulated other comprehensive income (loss) attributable to those derivatives is reclassified into earnings over the remaining life of the hedged debt.
Fair Value of Financial Instruments	The Company’s cash and equivalents includes institutional money market accounts which permit daily redemption and the fair values of these investments are based upon the quoted prices in active markets provided by the holding financial institutions, which are considered Level 1 inputs in the fair value hierarchy. The fair values of these accounts were $25 million and $228 million at March 31, 2019 and September 30, 2018, respectively. The Company’s remaining cash and equivalents, excluding restricted cash, were $661 million and $913 million at March 31, 2019 and September 30, 2018, respectively. Short-term investments are held to their maturities and are carried at cost, which approximates fair value. The short-term investments consist of instruments with maturities greater than three months and less than one year. Long-term debt is recorded at amortized cost. The fair value of long-term debt is measured based upon quoted prices in active markets for similar instruments, which are considered Level 2 inputs in the fair value hierarchy. The fair value of long-term debt was $18.2 billion and $18.8 billion at March 31, 2019 and September 30, 2018, respectively. The fair value of the current portion of long-term debt was $3.0 billion and $1.9 billion at March 31, 2019 and September 30, 2018, respectively. All other instruments measured by the Company at fair value, including derivatives and contingent consideration liabilities, are immaterial to the Company's consolidated balance sheets.