Accounting Changes (Policies)	3 Months Ended
Accounting Changes (Policies)	Dec. 31, 2017
Accounting Changes and Error Corrections [Abstract]
New Accounting Principle Not Yet Adopted	New Accounting Principles 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 is currently evaluating the impact that this new lease accounting standard will have on its consolidated financial statements upon its adoption of the standard on October 1, 2019. In May 2014, the FASB issued a new revenue recognition standard. Under this standard, revenue will be recognized upon the transfer of goods or services to customers and the amount of revenue recognized will reflect the consideration to which a reporting entity expects to be entitled in exchange for those goods or services. The Company intends to adopt the standard, as required, on October 1, 2018 and completed an initial assessment to identify the potential areas of impact that this new revenue recognition standard will have on its consolidated financial statements. As part of the initial assessment, the Company reviewed a representative sample of its contracts across its various businesses and geographies to identify potential differences that could result from applying the requirements of the new standard. The analysis included identifying whether there may be differences in timing of revenue recognition under the new standard as well as assessing performance obligations, variable consideration, and contract costs. The Company has not yet estimated the impact of the new standard on the timing and pattern of its revenue recognition. The Company continues to evaluate the available adoption methods, and apprises its audit committee of the project status regularly.
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. generally accepted accounting principles, 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, 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.
Derivatives	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. 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 effects these derivative instruments and hedged items have on financial position, financial performance, and cash flows are provided below.
Fair Value of Financial Instruments	The Company measures the fair value of forward exchange contracts and interest rate swaps based upon the present value of expected future cash flows using market-based observable inputs including credit risk, interest rate yield curves, foreign currency spot prices and forward prices. 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 $22.7 billion and $19.2 billion at December 31, 2017 and September 30, 2017, respectively. The fair value of the current portion of long-term debt was $703 million and $206 million at December 31, 2017 and September 30, 2017, respectively. The contingent consideration liabilities were recognized as part of the consideration transferred by the Company for certain acquisitions. The fair values of the contingent consideration liabilities were estimated using probability-weighted discounted cash flow models that were based upon the probabilities assigned with regard to achievement of the contingent events. The estimated fair values of the contingent consideration liabilities are remeasured each reporting period based upon increases or decreases in the probability of the contingent payments. The Company’s policy is to recognize any transfers into fair value measurement hierarchy levels and transfers out of levels at the beginning of each reporting period.